Today you are able to stream your Sirux XM subscription on your Amazon Echo (Alexa) device. You simply need to visit this page to set up the streaming provided you have a qualified plan, as well as enabling the skill in the Amazon Alexa app.
I have tried the stream on my Amazon Echo and it took some time to get Alexa to understand me when I said Sirus. But eventually, I figured out how to pronounce it the way she likes it. Luckily for me my car came with a sub to Sirus XM.