I believe that each person who might choose to identify as a leather pagan would probably have individual reasons for doing so. There are some gay covens in the Bay Area, but those groups are private so I can't really comment on them and how spirituality and sexuality are linked for them.
There are pagan groups that strongly work with certain goddesses or energies and try to incorporate beliefs that are part of the leather lifestyle, but all of these are small, eclectic practicioners, not something organized.
