The term “subsidized” means that at least 50% of the cost of the coverage is paid by the employer (Sec 35(f)(1)).
So you are correct that if your employer is paying less than 50% of the cost, you're good to go with regard to using the self-employed health insurance deduction for your wife's premiums. Remember that you can only deduct up to the amount of her business's net profit.
Filing jointly doesn't affect your ability to take this deduction.
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
