IMO the wording is so poor that it does not allow you to use the same circuit for more than one bathroom even if that's the intent. You can have multiple receptacles in a bathroom on the 20 amp circuit.
IMHO a problem is the broken parallel construction.
The alternative texts are intended to be
1. "a bathroom receptacle", and
2. "bathroom receptacles".
Grammatically the "a" modifies receptacle, not bathroom.
A typographical convention I propose for this type of alternative construction would be:
"...)a( bathroom receptacle(s)." indicating that you have either "a" or "s" depending.
:angel:
FWIW if infiniity's meaning were intended, the text should read "...a bathroom's receptacle(s)" or, avoiding the hassle completely, the receptacle(s) in one bathroom.
I think that they were trying to avoid the interpretation that they were requiring two or more receptacles, and hit a different snag in the process.