I am covered 100% on an employee sponsored plan, can I deduct the cost I pay to add my wife who is self employed?

I am assuming you are asking about health insurance.  If not, please post a comment below.  You cannot deduct it if the amount you pay for your wife is also deducted pre-tax on your paycheck. 

If you have a health insurance policy outside of work for your wife, then you can deduct the cost you pay.  But, you can only deduct it if your employer does not offer a plan for your wife.