Wolbel in left front wheel - 1998 Pontiac Bonneville

My guess would be you have a bent wheel. But first check the lug nuts to make sure they are all tight. If they are tight, jack up the vehicle enough to get that wheel off the ground. Grasp the top and bottom of the tire and see if there is any play. If you feel play or movement in/out then you may have a worn or loose wheel bearing or steering or suspension parts are worn. Spin the tire and see if it is tracking straight. If you see a wobble then the wheel is bent. The best thing to do is take the vehicle to your nearest trusted place that sells tires and have that wheel/tire assembly inspected. It can also be a defective tire but not likely. If you need a new wheel go to your nearest salvage yard and buy a replacement. Far cheaper than buying from a dealer.

Does the steering wheel shake side to side while driving it as well? this may be due to a separated tire or bent rim.