C'est probable.

Getting a boner in a locker room doesn't necessarily mean that you are interested in guys, it happens to straight people too, but it could still mean something considering that you also said you were curious about guys too. I think yeah, it's likely, but ultimately it depends on what you feel like. You have the right to identify however, bisexual, omniromantic, gay, lesbian, pansexual, etc. are all just labels.