Starting today, users who use Spotify and the Amazon can now stream music to multiple rooms, thanks to Amazon adding in support for multiform audio a few months back. Since its introduction multi-room audio has only worked with Amazon’s own music service, Amazon Music Unlimited.
So as of today, multi-room audio on the Amazon Echo works with Spotify and SiriusXM. Spotify on multiple speakers will only work in the US, UK, Canada, Ireland and Germany. SiriusXM only has support for the US.