"When using the AA interface, yes it keeps playing and would keep playing even if you really fully power off the phone. The phone is just commanding the AA what to do. The AA is the server."

Exactly what I wanted to know. Thank you!

When I use Spotify with my Chromecast, I can kill the power to my phone and the Chromecast keeps on playing. I am glad to hear the AA behaves the same way.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated