I'm union, and my union is highly supportive. They have a contingent march in the Pride parade every year, we have lots of out gay members, and several other members who have transition as union member, under our health plan which covers all of it. Of course we had a history of that as we cover make-up artists, costume/wardrobe people and set decorators in movies, TV and theater so it's had a very gay aspect to it historically. Hell, there is even a picture of me on the wall of shame at the office, dressed to the nines in fetish slutwear, tool-belt around my waist doing the rigging for one of the big fetish events here. They point to it to show how accommodating we are to clients needs. (Me, I was thinking, 'damn, and they pay me for this.') But, it the IATSE local in San Francisco, so it may not be an accurate model for all trade labor unions and locals.
First they are going to follow the law, or make every appearance of it. Second many unions have fairly socially progressive policies because they have long been associated with progressive politics and the progressive coalition. However, what the national policy may state is really up to the locals to determine, so I'd look and see how they treat out and obvious gay and lesbian members and use that as a guide.
Also, since status and seniority are pretty much sacred to unions, even if they don't much cotton to the whole TG thing, they would be loathe to do anything that would be seen to go against those two principals. You know, 'you can always tell a journeyman, but you can't tell them much.' And once you reach that full member/journeyman level you're pretty much in for life barring some beyond the pale screw-up.
The other thing is that your honey has real skills. It's not like working at a call center, or being a clerk, or doing customer service where any employer can pretty much go out and grab the next person walking down the sidewalk to replace you. Electrical work has to be done to code, and it takes years to learn that, so you've got that going for you too. And, if your sweetheart is a IBEW journeyman there is nothing to prevent moving to another local and working there.
