Location should have no affect on bluetooth. Think of bluetooth as a 30ft bubble all around you. The closer you are to the bluetooth device the better the signal.
How do you plan to listen to music? The amp doesn't have to have special inputs... the important part is what is playing the music you want to amplify to those four 6x9's.
You could use a phone and stream it bluetooth but would need an interface to send the signal to the amp. Unless the amp was a bluetooth amp.
A portable MP3 player. You can run the cable from the player to the amp. You would use a headphone to RCA cable of a good 20ft.
A hide away head unit. Then just connect like a typical head unit.
OR, if you are using your phone and want to use the USB-C out to send the signal to the amp...
Link to the Cable