You say one concern is that your bipolar. Is that you are concerned you may be bipolar or that you know you are bipolar and your wondering about medication interactions?
Im no expert on HRT at all, but I do know a thing or two about mental health. (not chemical interactions of different meds).
If you are bipolar and have been deemed stable enough to be absoloutly certain as to how you feel about HRT, Im not sure what the problem would be.
However, I believe a requirement (dont quote me on this) is that you have no psychological issues. If bipolar depression is treated with medication and controlled, it is no longer a 'problem' for people so to speak. You learn to live with it and can get on with little or no problems with it.
The only thing I could see being a problem would be if there was an interaction between meds eg lithium / anti depressants / anti psychotics + HRT. Like I said earlier, I dont know anything about interactions, just the mental conditions.
No matter what happens, if you are taking medication for bipolar depression, you absoloutly must under NO circumstances stop taking it unless you have been instructed to do so. Im sure you understand why

On the other hand, if you are just worried that you
might be bipolar, that is one thing you will have to resolve regardless of your life situation.
Ive been through more than most in this kind of thing, and far less than a lot of people on this site will have been through. But its all possible

Keep at it, take care, keep us posted.x