Yes, but if you exclude transgender from the notion of bisexuality, then you muddy the waters a little too much. So, for example, there are plenty of heterosexual men who are attracted to transgender girls. I am firmly in the belief that bisexuality is the most abstract category for sexual orientation, and that all of the other categories are mere determinants of this category. You can derive everything from the binary play of gender that bisexuality encompasses. Pansexuality, as I understand it, is not properly a sexual orientation (which is based on gendered relations), so much as a sexual disposition which favors personality over body, an attraction to the personality over the sex of the body. That is, pansexuality is an identity which seeks to step outside of sexual orientation altogether; or at least, that is the only way the identity carries significant meaning.