E-cigs give off water vapor. There's no reason for them to be banned anywhere except for cosmetic reasons. (someone doesn't like the look of someone smoking), To answer your questions, since E-cigs ARE non-smoking, yes, they are allowed.
I always ask the egotistical "do goodies"...do you drive a car? Does it have a/c? What is your house made out of and does it have a/c? Your perfume stinks to high heaven and your kids are mindless little consumers!...Works for me!