I was reading the various topics and noticed this one, I think i have an response.
If your insurance policy came with a book or a PDF in the back you can look at whats excluded. I actually just took out a private insurance policy myself with Blue Cross/BS and it says in the exclusions anything related to transexual care is excluded , i'll see if I can copy and paste what they have written, just a sec
Ok here " Transsexual treatment,surgery,medications and related services" are not covered, and it even has a warning that this is just a small list (A full two pages of exceptions they won't cover) and to contact them for the full-list. But your plan could be different from mine. Also pre-existing conditions won't be covered for a full year, and I think they might consider being transgender a pre-existing condition, especially if you've seen a therapist before you got the plan.
But you should check the documents that include details about the plan and maybe call them to find out.