I am not sure understand the issue. You don’t add Amazon Music to a speaker, you have it as a ‘source’ in your app, that can be applied/played on any speaker in your system. The same with Alexa, you just need to ‘tell’ Alexa that you want a source to play on ‘room name’. If it’s working on your Beam, it should be working on the rest of your system. 

Did say I wasn't great at this stuff.

Thanks for your help it's much appreciated.

Cheers 

You’re most welcome. Not everyone ‘understands’ how the system works, they just ‘use’ it. Which is fine, in my book. 

FWIW, I think you can ‘add’ Alexa to other speakers, but you’re just effectively adding the ability for those speakers, which have microphones, to ‘hear’ your command, and send it to the Amazon cloud for processing before it returns to your speakers. It isn’t really necessary, I controlled a whole bunch of Sonos devices for a long time with an Echo Dot, and not one of the Sonos had ‘Alexa’ installed.