Best answer by Misfit
Once it's set up, you'll be able to use it as a standard "dumb" soundbar. You will need to pair a remote to it during setup though, seeing how you wont be able to use the phone to control the volume. Either an IR remote or the buttons on top of the speaker.
It just won't be able to stream any music without an internet connection....and again, a caveat....you might (and I'm really not sure about this) be able to connect to it using AirPlay 2, so you might be able to stream music from your phone. Definitely will work while connected to wifi, but I'm not sure how AirPlay 2 will react with no wifi. It may not work at all, I can't promise. AirPlay 2 is a confusing (to me) standard of mixed connection profiles.
Wont work. You need WiFi for Airplay.