1997 Cadillac Deville My car pulls to one side

I have a 1997 Cadillac Deville and it has steering problems. When I drive my car it pulls to the left. I thought it needed a wheel alinement so I took it to a shop. I was told that my wheel bearings were bad and they cant do a wheel alinement until they replaced the wheel bearings. Most people tell me your wheel bearing are bad when thay make sounds but I dont hear anything, it just pulls. I took it to a tire shop and they said my tire had a good tread on the inside and where going to turn them inside out and balance the tire. They did but then it pulled to the other side. Does wheel bearing cause your car to pull or do I need new tire and a wheel alinement