He's a part of the Red Bull program. If Daniel Ricciardo gets a drive with Toro Rosso (or alternatively, fails to get a drive entirely), then I expect Vergne will be Toro Rosso's test driver in 2012 with a view to a race seat in 2013.
In fact, I very much doubt that Bianchi and/or Vergne could join Renault even if Renault wanted them to. They are part of driver development programs, and no doubt have exclusivity clauses in their current contracts. These clauses would give their respective teams - Ferrari and Red Bull - the right to make them the first offer to race. Renault would not be able to negotiate with them until such time as Bianchi and Vergne have rejected offers from those teams.
You seem to be misinterpreting my posts. I clearly said that the plan to get the French Grand Prix back does not demand a French driver in a French team (that's pretty much the mistake Alain Prost made when he established Prost GP). Indeed, it doesn't even require either of them - a French driver and/or a French team only make reviving the French Grand Prix easier. The only connection to Renault is Eric Boullier, who is on the taskforce to get the French Grand Prix back. If you read my post properly, you'd see that I spelt out a number of scenarios for a French driver to enter the sport (such as Grosjean going to a Renault-powered team, Bianchi joining Sauber, Vergne joining Toro Rosso). Romain Grosjean is not France's only hope.