He/She can do it two different ways and still be in full compliance with
the US NEC. One is a single twenty ampere circuit serves only the basin
receptacle outlets in one or more bathrooms. The other is that the
twenty ampere circuit can serve the receptacle outlet in one bathroom
only as well as other loads in the same bathroom. Both approaches are
allowed but you cannot combine them. I prefer to run one dedicated
twenty ampere circuit to each bathroom basin receptacle outlet. Since
the hairdryers that are used today take the entire ampacity of a fifteen
ampere circuit to run them a second hair dryer would push a twenty
ampere circuit over the trip point of it's breaker. If I do what the
code allows and run two different bathroom's basin receptacle outlets
from the same twenty ampere circuit then one hair dryer in each would
trip the circuit. If the bathroom has auxiliary heat I use a multi wire
branch circuit to supply the heater and the basin receptacle outlet. If
future code changes require the use of AFCIs in bathroom circuits I'll
just run dual circuit cable instead. Leaving at least one light in the
bathroom on the general lighting circuit so that the tripping of a
receptacle circuit will not plunge the room into darkness is my idea of
good practice and common sense.
--
Tom Horne

"This alternating current stuff is just a fad. It is much too dangerous
for general use." Thomas Alva Edison

.... ... wrote:
One 20 amp circuit for the gfci only.Check the NEC.