You've nailed this. The NYC DMA includes Northern and Central Jerz, Westchester, LI, and the City proper. Rutgers obviously won NJ handily and trumps our smaller victories in the remainder of the DMA.
Most Westchester and LI folks wouldn't be caught dead rooting for a Jersey team. That's just reality. I'm sure there is no way to prove it but its safe to say we would be higher rated in those areas. The actual city of NYC, nobody cares and both ratings are probably miniscule.
Seeing that NY State as a whole cares much, much more about Syracuse (upstate, Westchester, and LI), why can't we call ourselves NY's College Team? Rutgers tries to refute this because they stick Jersey into the NYC DMA and pass it off as though Manhattan loves Rutgers. Anybody who lives around here knows better.