We have that exact model Airstream towed by a 2012 Ram 1500
. I am sure the hitch (tongue) weight is over 750#, it would need a weight distribution hitch, and the Touareg hitch reinforced.
If you can manage the payload limits of the Touareg (similar to our truck) I believe it would be a better tow vehicle than what we have because of it's excellent suspension and powerful, efficient diesel engine.
Coming from a Sport 22 I think you will be as pleased with the spaciousness, capacities, and towing of a tandem axle 25' as we were coming from a 20' single axle.