To bestow my bluntness and honesty, I would be pretty upset if the man I was with was secretly married, while marrying me. You have broken her trust in a huge way.
That being said, she gave you an ultimatum? Marriage is something that should be between two people who both, independently of each other, want to. Forced marriage breeds resentment.
If by 'holding against you' you mean always using it in arguments, always bringing it up as a means to win the conversation... if she's said she forgives you then this is out of bounds. However, if she hasn't forgiven you, this is part of her getting her anger and hurt out. If you truly want to be with your new wife and want to make things work, you should own up, tell her you realize you broke her trust and how badly you feel, validate her feelings, tell her you're going to show her moving forward that she can trust you (and do so), and that you hope in time she can forgive you.
Then do something nice for her that will make her feel that you love her so. Don't make a common mistake though, by letting yourself become a doormat in the process of making it up to her. You're an individual like any other and we all make mistakes, sometimes big ones, but mistakes none the less. If the offender is truly sorry and is trying to make things better, they should not be treated like a bad puppy.
Sort of went on a rant there...
Hope this helps :)