Well, I'll start with the stock answer of 'neither,' as wireless is not a preferred way to send any audio or video.
With that said, if you must, then it really comes down to distance. Bluetooth has a very limited range, but more secure and reliable with good equipment, whereas Wifi will work at much greater distances.
None. They do not provide much power and small. I would rather have the speaker connected to a power amplifier or a receiver than can power lots of power.
