Can bathroom lights be on same circuit as bedroom lights?
Yes. There's nothing different about bathroom lights vs bedroom lights. In fact, I would say it's a bad idea to tie the bathroom lights to the bathroom outlet (which should be a GFCI). Otherwise you drop your hair dryer and suddenly you're in the dark!

The only thing you might need to consider is that bathrooms tend to have exhaust fans on the same circuit as the lights. These tend to draw more amps than a light, so make sure you don't overload your circuit.