Power from the drive wheels:
The Bush Winch can operate off any wheel that has power to it and therefore can be on a 2WD, AWD or 4WD vehicle. Normally the two winches supplied are attached to either side of the same axle, front or back. However, if traction was lost just lost to the wheel on one side, say in a ditch you would only have to attach the winch to this side, effectively stopping the differential from working and forcing the other wheel to turn.
Given that the Bush Winch uses the vehicles engine power is effectively limitless and well above what is otherwise available from alternative like electric winches. As long as your engine is going you can winch. No batteries, no switches or cables or devices needed.
Vehicles with TC and/or a Diff Lock works well with the Bush Winch but at the same time it is not necessary to have either. A winch rope that is a closed loop coming of the winch on one side of the vehicle, goes forward around the anchor and back on the other side of the vehicle will prevent the Diff from working; effectively the same as a Diff Lock. Of course if your vehicle already has Diff Lock you could consider just winching off one side.
A tight winch line from the wheel will signal to the vehicles TC system that it has traction even when it doesn’t and will therefore allow power to be applied to the wheels. Your vehicle will winch until the tyres have got traction again. If you can turn the TC off in your vehicle you may find winching with no input for the TC system is preferable but in either case the Bush Winch and TC systems work well together.