Glad you found a way to make it work for you. Vera scenes will be useful for creating scheduled Roomba tasks (clean this space at 9 am every Monday), or getting automatic alerts when the battery reaches a certain level.
You shouldn't need to have the Vera involved at all, if all you want to do is use voice control.
The example that Nighthawk provides on the Vera forum can be done with the Scrape action.
Per Nighthawk's post:
http://forum.micasaverde.com/index.php/topic,17560.msg204689.html#msg204689Instead of creating a scene with his luup code (and doing that again and again for every command), you would enter the same URL in the scrape action.
So the action where currently you're calling a Vera scene in VC, replace that with Scrape >
http://ipofyourroomba/command.json?command=clean.
You can probably even create a payload xml file with the different commands endings (clean, dock, etc), and use mostly just one command in VC.