BTW, I don't have a paid Amazon music plan because I liked Pandora better, and because Amazon unlimited music would never function properly on my Echo. CS never sorted that issue out so I didn't purchase an unlimited plan. But with Pandora, I can listen to it on any device that has their app, and I can stream it via BT to other devices like the Echo, my car radio, BT speakers, etc. However, Pandora will refuse multiple connections or streams. I assume Amazon will do the same unless you have the multi-device plan.

I think what is interesting with this additional feature to Echo devices to allow streaming via BT to third party speakers is that perhaps this is Amazon's way of admitting that the speakers in the Echo really are not that great. My iPad Pro 9.7 sounds way better than my Echo. My Dot has way better voice sound than my Echo. My Echo sounds like it is sitting inside a 55 gal drum--kind of muffled. It is okay, but my TV and other devices seem to have better sound. BTW, I think this feature has already been available for Dots. I think I was allowed to connect my Dot via BT to my stereo, though I never did so.