Health Benefits - New Policy on Spouses

My company just opened us up to annual enrollment and I was notified if my spouse has available health insurance benefits and chooses to stay on my plan I will have to pay a surchage/fee of $600/yr if I keep her on my insurance.

Couple other facts. When wife accepted the job she indicated she didn't need the benefits and its a small business so was used in her salary negotiation for more base pay. I do not believe it was ever put in writing, but it was agreed to verbally. Also, her insurance blows and is more expensive substantially - more than $600 - so going on her insurance is not an option even if her boss would allow it.

So couple of questions for the MB:

1. Is it legal to do this in Louisiana? I work from home for a fortune 1000 company based in Atlanta and there are a handful of remote employees at most in LA.

2. Since there was a verbal agreement when my wife took the position that she would not take benefits would that be enough to satisfy the requirement? And no I am not going to ask HR.

3. Should I just put she doesn't have health benefits available because there was a verbal agreement in place?

I am leaning towards option 3. There is no evidence requirement that I can find so I think the verbal agreement at least gives me something to stand on.

Thoughts?