First, visit my webpage on vibration, balance, and uniformity. It explains some issues about how tires (and wheels) affect things.
http://www.barrystiretech.com/unifandbal.html
Short version: Vehicle suspensions are primarily affected by the first harmonic of the uniformity of the rotating components. The first harmonic is the once per revolution component. It's the first harmonic because that harmonic is generally larger then the other harmonics.
What the suspension is reacting to is the resonant frequency of the spring/mass/damper system that is the suspension. Actually, there are 2 S/M/D systems - the suspension and the tire.
Some vehicles are more sensitive than others to these vibrations. I don't have enough experience to tell you what parameters are important except to say that the relative masses seem to pay a role - that heavier suspension components seem to help. This is, of course, the opposite direction that vehicles are going.
The steering wheel reacts to the front suspension, while the rear suspension is generally felt through the floor or the seat back.