There is definitely a correlation between successful programs and recruiting rankings. It just isn't absolute. Most of the best programs in the country are at the top of the recruiting rankings yearly. There are outliers to that of course, Wisconsin is the best example in the Big Ten, and MSU seems to be joining them. On the flip side, programs like Notre Dame, Texas and UCLA have been near the top of the rankings and haven't performed as well on the field.
As for Michigan, RR actually did worse in the rankings than is typical of Michigan, and then we had a BIG transition to Hoke. He's had two great recruiting classes, which are currently true sophomores and freshman. It's too early to judge his recruits, but I'd say the early returns are mixed so far (mostly good on defense, mostly bad on offense).