In order to get a premium tax credit, the insured person must pay for the health insurance themselves. The PTC is a subsidy to help pay the cost of the health insurance. For clergy, the housing allowance is not added to their income when determining the amount of PTC.
If the taxpayer received the PTC, they would receive a 1095-A form at the end of the year that would compute the amount of PTC to be reimbursed if it was overpaid.
In your example, none of this would apply because the church is paying for the insurance.
