I also just purchased a Rhino Rack Batwing Awning and saw the following on Rhino's site:
Batwing tappered Zip Extension
With 4 Tapered Zip Extensions attached together on your Batwing Awning, you can create a full enclosure for your family and friends.
They also have the Batwing/Sunseeker Awning Extensions that you can use as walls:
Batwing/Sunseeker Awning Extensions
The problem is these are just walls, that have no windows or doors, so it's more protection than an actual room, like Alu-Cab's Room for their Shadow Awn.
The Mesh Floor would help in creating a room too:
Batwing Mesh Floor Saver
I haven't seen anything else at this point for the Batwing, I do think if the extensions above could be fitted with mesh windows and a door, it would truly make for a room.