To send audio from the receiver to bluetooth speakers you would connect a BT transmitter to a fixed line level (record) output on it. Any analog source would work. Digital sources might not since many receivers won't convert digital to analog.
To send audio from you phone to it you would connect a BT receiver to an input of it.
You could pair the phone with the BT receiver and the BT speakers with the BT transmitter to get it to work.
You may notice delay problems if you can hear the BT speakers in the receiver room. Low latency BT gear will minimize but may not eliminate that.
The best solution would be to us Sonos or Denon Heos products. Much more flexible. A Sonos Connect or HeosLink would act as both receiver and transmitter for...