Thanks for the question. Are you using the 791's with an SA-5 amplifier? If so, you can use Bluetooth to the SA5 to play audio to the speakers. The method of using a wireless hotspot, while not technically supported by Bose, may work for you.
If you have any further questions, please let us know.
Do you have the SA-5 setup on the hotspot? From there you can get into the Bluetooth settings on the SoundTouch app and make the system discoverable, which can then be seen by your phone.