I have a mp3 bluetooth player attached to my outside bar. I also have sonos wireless sound system. can these be linked toght

[mvol]

looking to connect a Bluetooth system and sonos wifi to play in sync

 

[Alabalcho]

Bluetooth is one-to-one communication (and in this case, audio) protocol.

In you case, I would feed split audio out of your MP3 player in two (one feeding Sonos, the other one feeding Bluetooth transmitter paired with your outside bar).