Because both you and your wife were self-employed and paid for the insurance with post-tax funds, it is a legitimate deduction for your self-employed business expenses. It does not matter that the premiums were employer- sponsored/subsidized coverage.
The fact that you paid with post-tax dollars is what makes the premiums self-employment expense eligible. Be careful not to take the same deduction on your self-employment expenses and on your personal expenses. In most cases, you will have a more favorable return with self-employment, then with using them as an itemized deduction on Schedule A.
