I hope I've read your question right...
Subsonic has the ability to stream music to Sonos devices and Subsonic can act as a DNLA-server.
If you've just installed your subsonic server you would be finding this under Setting >> DNLA/UPnP and Settings >> SONOS.
After 30 days you'll have to buy a license to use these features. For details see
http://www.subsonic.org/pages/premium.jspThere you will also find that using 3th party apps to connect to your subsonic-server requires a license too.
"Upgrade to Subsonic Premium to enjoy these extra features
•Apps for Android, iPhone, Windows Phone, Mac, Chrome and more*.
•Video streaming.
•Your personal server address: yourname.subsonic.org
•No ads in the web interface.
•Stream to your Chromecast and Sonos devices.
•Podcast receiver.
•Play your media on compatible DLNA/UPnP devices.
•Share your media on Facebook, Twitter, Google+.
•Other features to be released later."