Do I have a case of constructive termination based on dating a co-worker

I have been dating a fellow office worker for over 2 years. The company has only been aware of the situation for the last seven months. Now without warning I am being forced to work in a different office further from my residence, for a former manager that admitted to the person I was dating that she didn't care for me. I am a 100% commissioned sales recruiter and am also being relieved of handling the company's #1 producing account when I make the move. I produced the highest sales in this account last fiscal year and also have a supporting letter from this client company stating what a great job I have done. In addition I made a copy of a handwritten letter from my current office manager stating that once our understaffed office "hires 2 more, that they are going to get _me_ out. "Still not sure these 2 can work together,". Can they do this and what rights do I have in California? There was no specific clause about coworkers in the same office not being able to date in the employment contract I signed and there was no accompanying employee handbook.

Is the person you are dating in a supervisory or managerial position? If so, the company has a legitimate business interest in protecting itself against potential claims in the future for sexual harassment should this relatiinship go sour. Also, transfers are not necessarily considered punitive in nature.
Since many factors are missing from what you have posted, you may want to explore this more fully with and attorney who handles Employment issues on behalf of employees - it may be well worth the cost of a cunsultation if your are losign income or status as a reasult of these actions.