Of course you can WL in V (you can pretty much list any class, but below V it makes no sense) the only problem is the booking will be cancelled if you don't ticket with the limit. So if the time limit for the fare you want to use is 24h, the booking will be cancelled the next day if your WL for V didn't clear. If you ticket V/Q, you have to do a reissue when V clears, and I suppose the fare difference is less than the change fees....