Hello Stefanlind,
As Arminlerch has already written, you can't link the systems, but you can operate them independently, provided of course that the WLAN has enough bandwidth. Unfortunately, each manufacturer still has its own system, and there is currently no overarching standard for Multiroom. However, Bose offers the SoundTouch Wireless Link adapter with which you can integrate any loudspeaker / stereo system into the Soundtouch. This is something like the logic of the Soundtouch with a lineout. Maybe this is a solution for you if you can't find a suitable Bose Soundtouch speaker?
Or why do you want to pair Sonos and Bose at all?

Hello, Sonos and BOSE cannot be paired. However, they can be operated in the same WLAN.