The governing body of the church can do what they agree to do. Whether this is the RIGHT thing to do could only be considered effectively by the same governing body. This body knows the salary being paid and whether the bonus is merited. It could be the best interest of the church to do something in the community with this extra money.
If it goes as a bonus, do not forget to add it as extra income on the pastor's yearly W-2 form. Good luck in your decision.