Yeah, he is.
“On gay marriage, I support it, at both the state level and the federal level. Gay marriage is something I’ve thought about at length as I’ve looked at my future. I concluded, a couple years ago, that I think it should be permissible and treated the same at both levels.”
http://www.afer.org/blog/john-bolton-expresses-support-for-marriage-equality/
Hey!
A queer has as much right as the next guy, to marry a woman.