There should be some useful info for you in the following thread:
Bluetooth DAC discussion
Bluetooth DAC discussion
Does anyone have experience with the bluetooth DAP's? There's 4 main ones that I'm looking at (BTR3, BTR5, ES100, ES100mk2) all at varying price points. I'm quite sure they all sound very similar (if not the same if you subtract placebo), but I'm not sure what the practical differences are. On an IOS device.