What is claimed is:1. A Bluetooth communication system (100), comprising:a Bluetooth host device (110), comprising:a host-side communication circuit (111);a host-side cypher key generation circuit (115); anda processing circuit (117), coupled with the host-side communication circuit (111) and the host-side cypher key generation circuit (115), and arranged to operably control operations of the host-side communication circuit (111) and the host-side cypher key generation circuit (115); anda Bluetooth device set (102), comprising at least a first member device (120) and a second member device (130);wherein the first member device (120) comprises:a first communication circuit (121), arranged to operably conduct wireless communications with the host-side communication circuit (111);a first cypher key generation circuit (123); anda first control circuit (125), coupled with the first communication circuit (121) and the first cypher key generation circuit (123), and arranged to operably generate a first resolvable set identifier (RSI-1) corresponding to the first member device (120) according to a device set identification information corresponding to the Bluetooth device set (102), and arranged to operably utilize the first communication circuit (121) to transmit a device information of the first member device (120) to the Bluetooth host device (110);wherein the second member device (130) comprises:a second communication circuit (131), arranged to operably conduct wireless communications with the host-side communication circuit (111); anda second control circuit (135), coupled with the second communication circuit (131), and arranged to operably control operations of the second communication circuit (131), and arranged to operably generate a second resolvable set identifier (RSI-2) corresponding to the second member device (130) according to the device set identification information;wherein the processing circuit (117) is further arranged to operably control a display device (150) to display a candidate device list, and to display a single device item for representing the Bluetooth device set (102) in the candidate device list, but does not simultaneously display two device items for respectively representing the first member device (120) and the second member device (130) in the candidate device list;wherein the processing circuit (117) is further arranged to operably utilize the host-side communication circuit (111) to establish a connection with the first member device (120) and to conduct a pairing procedure to generate a first cypher key (Key-1) after receiving a selection command issued by an user;wherein the first control circuit (125) is further arranged to operably utilize the first communication circuit (121) to establish a connection with the Bluetooth host device (110) and to conduct a pairing procedure to generate a second cypher key (Key-2) corresponding to the first cypher key (Key-1);wherein the first control circuit (125) is further arranged to operably generate a third cypher key (Key-3) and a corresponding fourth cypher key (Key-4);wherein the processing circuit (117) is further arranged to operably use the third cypher key (Key-3) to conduct Bluetooth data transmission with the second member device (130), and the second control circuit (135) is further arranged to operably use the fourth cypher key (Key-4) to conduct Bluetooth data transmission with the Bluetooth host device (110).2. The Bluetooth communication system (100) of claim 1, wherein the first control circuit (125) is further arranged to operably utilize the first communication circuit (121) to transmit a device information of the second member device (130) to the Bluetooth host device (110).3. The Bluetooth communication system (100) of claim 1, wherein the first control circuit (125) is further arranged to operably utilize the first communication circuit (121) to transmit the third cypher key (Key-3) to the Bluetooth host device (110), and to operably utilize the first communication circuit (121) to transmit the fourth cypher key (Key-4) and a device information of the Bluetooth host device (110) to the second member device (130).4. The Bluetooth communication system (100) of claim 3, wherein the processing circuit (117) is further arranged to operably utilize the host-side communication circuit (111) to establish a connection with the second member device (130) after receiving the device information of the second member device (130);wherein the second control circuit (135) is further arranged to operably utilize the second communication circuit (131) to establish a connection with the Bluetooth host device (110) after receiving the fourth cypher key (Key-4) and the device information of the Bluetooth host device (110).5. A Bluetooth device set (102) of a Bluetooth communication system (100), comprising:a first member device (120), comprising:a first communication circuit (121), arranged to operably conduct wireless communications with a Bluetooth host device (110) in the Bluetooth communication system (100);a first cypher key generation circuit (123); anda first control circuit (125), coupled with the first communication circuit (121) and the first cypher key generation circuit (123), and arranged to operably generate a first resolvable set identifier (RSI-1) corresponding to the first member device (120) according to a device set identification information corresponding to the Bluetooth device set (102), and arranged to operably utilize the first communication circuit (121) to transmit a device information of the first member device (120) to the Bluetooth host device (110);a second member device (130), comprising:a second communication circuit (131), arranged to operably conduct wireless communications with the Bluetooth host device (110); anda second control circuit (135), coupled with the second communication circuit (131), and arranged to operably control operations of the second communication circuit (131), and arranged to operably generate a second resolvable set identifier (RSI-2) corresponding to the second member device (130) according to the device set identification information;wherein the Bluetooth host device (110) controls a display device (150) to display a candidate device list, and to display a single device item for representing the Bluetooth device set (102) in the candidate device list, but does not simultaneously display two device items for respectively representing the first member device (120) and the second member device (130) in the candidate device list;wherein the Bluetooth host device (110) establishes a connection with the first member device (120) and conducts a pairing procedure to generate a first cypher key (Key-1) after receiving a selection command issued by an user;wherein the first control circuit (125) is further arranged to operably utilize the first communication circuit (121) to establish a connection with the Bluetooth host device (110) and to conduct a pairing procedure to generate a second cypher key (Key-2) corresponding to the first cypher key (Key-1);wherein the first control circuit (125) is further arranged to operably generate a third cypher key (Key-3) and a corresponding fourth cypher key (Key-4);wherein the Bluetooth host device (110) is further arranged to operably use the third cypher key (Key-3) to conduct Bluetooth data transmission with the second member device (130), and the second control circuit (135) is further arranged to operably use the fourth cypher key (Key-4) to conduct Bluetooth data transmission with the Bluetooth host device (110).6. The Bluetooth device set (102) of claim 5, wherein the first control circuit (125) is further arranged to operably utilize the first communication circuit (121) to transmit a device information of the second member device (130) to the Bluetooth host device (110).7. The Bluetooth device set (102) of claim 6, wherein the first control circuit (125) is further arranged to operably utilize the first communication circuit (121) to transmit the device information of the second member device (130) to the Bluetooth host device (110) before the first member device (120) and the Bluetooth host device (110) completing their pairing procedure.8. The Bluetooth device set (102) of claim 7, wherein the first control circuit (125) is further arranged to operably utilize the first communication circuit (121) to transmit the third cypher key (Key-3) to the Bluetooth host device (110), and to operably utilize the first communication circuit (121) to transmit the fourth cypher key (Key-4) and a device information of the Bluetooth host device (110) to the second member device (130).9. The Bluetooth device set (102) of claim 8, wherein the Bluetooth host device (110) establishes a connection with the second member device (130) after receiving the device information of the second member device (130);wherein the second control circuit (135) is further arranged to operably utilize the second communication circuit (131) to establish a connection with the Bluetooth host device (110) after receiving the fourth cypher key (Key-4) and the device information of the Bluetooth host device (110).