Constant squealing sound coming from right rear wheel

When I drive my car at highway speeds after about 15 mins I get a high pitch squealing sound coming from the right rear wheel. When I tap my brakes the sound will stop, but returns a few seconds later. The sound will also briefly stop if I change lanes or turn.
It took my tire off, removed the disc and caliper. When I hand spin the wheel hub it doesn't turn smooth like "butter". There is a slight resistance in the spin and makes a slight noise. I am not a car expert but would have thought that rear wheel hub (a front wheel drive car) should spin 100% uninhibited. It should should spin free and easy without noise yes?
This means that it is a wheel bearing problem correct?
It is still under warranty and I am bringing it in, but want to go in with knowledge so they are going to sell me new brakes for a wheel bearing problem.