This borders on a dumb question, but do the 10 nights from the Ibis card and the 20 nights from the Voyageur card stack? I ask because that would equal "instant Gold". I'd presume it doesn't, but...well, let's face it, this is FlyerTalk we're talking about, so I also think it would be silly not to ask.

(Annoyingly, the only Accor brand I have much use for is Fairmont courtesy of its old railroad hotel heritage...)