Alignment DOES NOT cause vibration. Your tires may be out of balance. I reccomend you re-balance your tires. Most tire dealers will re-balance your wheels for free if you are getting a vibration, and you bought the tires from them. Thats what you payed them for. If you're feeling the vibration in the steering wheel a front is most likely out of balance, if you feel it in your ass then it's probably a rear. Hope this helps

BTW: Welcome to HAN!!