The weight can still be shifted from side to side without the front wheels, so turning isn't the issue. Remember the cup of water from Initial D? If you keep the weight in constant transition from side-to-side then you can hold lateral momentum without input from the front wheels. In this way you can drift with your hands off the wheel if you're good enough!
The problem is that you'd have to accelerate so hard to maintain the wheelie that the drift becomes impossible except on very slight turns where the exit angle is easy to obtain. Even within those limits, it'd be a truly impressive feat because having enough traction to maintain a wheelie while sliding is tough. You better come correct if you try that move! Very few cars, if any, in this game would be able to do it. You'd need a purpose-built car that probably couldn't even be done with a Sharkport.
