Your car has low profile tires.

Potholes, road debris, all can cause bubbles in your sidewalls. Its the trade off made for better handling, and style. The only thing you can do is to keep your tires properly inflated, and to try and avoid the road hazards. Some tires are more prone to bubble than others, in your case, maybe you should thinking about getting new tires from a tire store, and getting their road hazard protection package. The dealer doesnt have any responibility for road hazard damage just like they dont have any responsibility from someone hitting your car.