I can say to my Beam (and my Sonos Ones) "Alexa - play Faith No More from Amazon Music". I have an Amazon Australia Prime account, which includes music, so it does exactly what I expect.
But if I try to link my account in the Sonos app, and try to browse the catalogue ... I get this message: Amazon Music is only available for Amazon accounts located in (list of other countries).
Meanwhile the Beam is merrily playing away from my Australian Amazon Music account, making a fool of the Sonos app. Clearly it works and is available.
Please fix this idiocy. Having only voice control over Amazon Music song selection on Sonos is stupendously annoying.