If you have a jack, lift it up to where the rear tire just clears the floor. Lay something on the floor like a piece of 4" x 4" close beside the tire leaving a small gap, put in neutral and turn the rear wheel while looking at the gap. If the wheel is bent, you can probably see the wobble. Better if you had something that would sit on the floor and curve around the tire to be close to the wheel. Like others have said, sounds like they might have bent your wheel.