I don't think that the cell phone network differences between the two devices is relevant. The only time that it would is if you were using a streaming radio feature, in which case, the service used would control the bitrate of the Audio File. The issue then would be the service being provided by the streaming entity. Each of these entities usually stream well under 128 kilobits per second, and both of these phones can handle audio quality higher than the stream. Similarly, both GSM, and CDMA networks can support 128 kbps quite easily, frequently exhibiting well over 10 times that data rate in bursts. Once the stream is established it is buffered, and the quality of the music depends entirely on the providing stream source.

If though, the Audio files are stored on the device, the differences of the two devices are a little more pronounced. Both devices support high fidelity files, and can play audio sources at higher quality than the majority of streaming services. The issue here is then the limitations of the headphones that you use, as both devices can handle higher quality than the shipping headphones.

Bluetooth headsets using a2dP Generally do not have as good of quality as wired headsets (in my experience). I'm sure there are probably exceptions on the higher end of the products. So if you are truly worried about sound quality and clarity, I would recommend choosing your phone independent of this issue, and study out which headphones might provide the best quality. Similarly if quality is the issue, I wouldn't try streaming music over either devices cellular network, as quality will be hindered with the intent of deliver (regardless of the phone). The quality wouldn't necessarily be any better per network protocol, but if streamed, would definitely depend on service levels in your area.

My conclusion is that neither device has a clear edge on the Audio Quality based on the network protocols that they use. If you really want quality out of the devices I don't think you would be disappointed by investing in either of them, and choosing a nice quality pair of headphones to go with them. From there it is wholly dependent on the quality of the Audio File that you obtain to play through the phone and headphones. The Audio File is truly where the quality / clarity issue comes in.

Bose is a name that is synonymous with quality audio

devices, and their latest foray would be the bose qc3
Acoustic Noise Cancelling headphones.