The answer to that is "It depends".
Different tracks favour different cars for different reasons - an AWD vehicle may well be faster around a track where the RWD car needs to back off to maintain grip for a significant amount of time, and can't press it's weight advantage (a tight, twisty track for instance). I believe AWDs are topping the quarter mile standings too at present only 4 of the top 10 are RWD, and the best one is in third place), and I believe they will extend that lead as the launching capabilities are further explored after recent developments that allow spooling of the turbos for a launch).
To use tracks I am familiar with as an example - Eastern Creek North Circuit is a power track, with top speeds down the main straight easily exceeding 200km/h, speeds up to 180km/h attainable by some cars between turns 1 and 2, and a decent back straight as well - I've no doubt that a RWD Stinger would have the advantage here.
South Circuit at the same place, would be much closer - the straights are shorter, and the track itself is shorter and has more corners.
Go to a track like Marulan, Wakefield or Luddenham, and they're shorter, tighter and more technical circuits, and I'd expect the AWD to close the gap if not take over.