Yeah I think this merits a bisexual tag. Hime doesn’t seem to have any problems dating men, she just didn’t end up doing so.
If you are only looking for yuri the bisexual tag is like more of a warning that there is an actual bisexual relationship or at least a girlxguy situation. That might cause some people not to read it.
I only steer clear of the "Bisexual" tag if it's paired with like "Love Triangle" or "Cheating" because then I know there's a solid chance there's gonna be some shitty stereotyping of bi girls going on and I don't have time for that but the tag on its own should only really denote the significant presence of a bi character. Like, what if someone is looking for stories about bisexual women in sapphic relationships without all that bullshit? Tags that are just descriptors of characters and not actually plot relevant are pretty common.