Two things. One, it takes a period of time for car tires to break in so to speak . Also I found through trial and error that my road glide ultra works best withe rear tire set at 36 psi and the front at 38 psi. Second, have you checked your tire swing (how tight the bearings in the neck are).. If it's not right this can contribute to the wobble you described. It's a simple procedure. Basically you jack the bike up, swing the handle bars to one side (forget which side), release them. They should swing all the way to the opposite side and back about 1/4 of the way back toward straight forward position.
Hope this helps.. I have 10,000 miles on my G-Max 205/55 16 rear tire and Avon 150/70 18 Road rider rear MC tire mounted up front.