Of course, I know nothing about Bluesound or similar products. So after reading your message, I called MD and talked with a knowledgeable person.
My essential question was, "OK. I subscribe to Spotify Premium. Say I have a B. Node 2 connected as part of my main rig, internet-connected via ethernet. In another room, I want to listen through non-powered, non-bluetooth bookshelf speakers. I have a small integrated amp for powering the bookshelf speakers. What else do I need to bring the Bluesound stream into this arrangement so that I can listen in the 2nd room?"
His response was that I would need another B. Node 2 unit. Thus, this would be $450 for the first unit, and then $450 for the additional unit to retrieve and make use of the sound in a 2nd room.
Now, keep in mind that I'm a know-nothing on this, so I could have gotten something wrong along the line. Does that sound about right for you?
Thanks again for your message. I enjoyed the research.