Yes you could use Bluetooth to play from the Amazon Music app to the Move. You may be able to cast direct from the Amazon Music app to any Sonos speaker (but I'm not sure if that is only available with Amazon Unlimited). 

I doubt that music is missing when playing through Sonos. Tbe Amazon search on Sonos is pretty awful and all searches tend to be poor with classical music.  I think that is a more likely explanation, although that is speculative.

Are you sure that the St Matthew Passion is available on the Prime subscription? 

I get lots of results from an S2 Sonos App search on ‘St Matthew Passion’ - more than I can display in a single screenshot on an iPad (as attached).

I ‘suspect’ the Sonos App search has not been expanded to show all the results, perhaps ?

There appears to be many albums with that title, so not sure which one specifically you are referring too.

However, searching in the Sonos app can be problematic/frustrating. I find it easier to use the Amazon Music app and add the album to a playlist, then come back to Sonos and locate it under Amazon Music > My Music 

@Mr. T . Is that Amazon Music Unlimited? The OP only  has Prime, which has a very limited selection of music. I am not sure it is even possible to search for specific pieces of music. 

Ahhhh, yes it is. Still, if they are able to view and play it on the Amazon Music app, I’d expect it to show under a Sonos search, even with just a Prime subscription, rather than Unlimited.

Thank you all for your prompt responses. V helpful. After further work using/learning Sonos search functionality, I was able to find the music I wanted. Peace and grace to you all….