The only way to connect BOSE and Sonos is via a line in. The two systems are not really designed to work together.

Thank you so much for your comments, my understanding is that there is a device that can connect several speakers of diffrent brands- I don’t remember tha device  name. I will continue exploring 

If you find such a device, I suspect there are many of us that would be fascinated. As suggested, there is already the Sonos Port, as well as several other speakers that support a line in, but all Sonos analog line ins would have a 75ms delay so that Sonos can buffer the input so that it can work in many rooms. Thus making it inappropriate for use with a soundbar of any make.