Bought a Bose 500 home speaker (cos they sound frigging amazing) and hooked it up to Alexa and spotify without touch much hassle. Problem came when we bought another one for the kitchen and wanted them on separate spotify accounts so we could play different stuff without affecting the other one. After a few hours of swearing, eye rolling and counting to ten leaving the room and coming back in etc I figured out what was required.
So to have them seperate, you need to have separate accounts for all services involved i.e
Bose account
Amazon account
Spotify account
Trick was to use another smartphone to setup the second speaker with Bose app (with new bose account) then link separate spotify service to the bose app. Then go to Alexa app and add the device, and then add the spotify and Bose non for Soundtouch skills again using a separate account than you used on the first speaker.
Hope it helps someone 🙂