My right rear wheel is quite hard to turn by hand when on jack compred to all sides, even with capiler removed. No griniding noise. Do ineed to replace bearing. I do have vibration in my car above 90 km/h. Sometimes my front end also feels loosy while turning on highway.

 

I would try to listen to the bearing while turning it. A long screwdriver makes a good stethoscope.
Under the hubcap you should find a 32mm nut, you can try to loosen it and then re-tighten to it's orginal position to see if the rotor becomes easier to turn.
Usually when the bearings go bad they make a growling noise when spinning at speed.