Do you feel it or see it? Tyres are usually fairly uniform and any wobbling is due to misalignments during install and getting the bead seated evenly all the way around. If you feel it, then it's an imbalance due to the extra metal at the pinned seam on the rim which isn't always offset by the weight of the valve-stem on the opposite side. Or if you've squeezed Slime into the tube, there's a lump of it in one spot that needs some speed and riding to smear itself around the insides more evenly... There's actually a product called BalancePlus for motorcycles that somehow balances a wheel with use, not sure how it works though...