750 watts is about 6 amps. The general rule in residential wiring is that a 15 amp breaker can be wired to 14 guage wire, and should have a continuous load not exceeding 12 amps. ( Short term uses like a toaster, or hair dryers, are not condsidered contiuous. A light fixture is.)
If there are no other loads on the circuit ,you are fine. If there are other loads, then you would have to evaluate the whole picture.