An apparent conflict of interest
You have an apparent conflict of interest. Although you did not file the zoning appeal yourself, others would suspect that your judgment might be biased by your personal relationship with your father. In other words, even though your professional judgment may be impeccable, the personal relationship would cause others to think that your judgment might not be fully reliable. Both a real conflict of interest and an apparent conflict of interest have the same problem: they reduce the trustworthiness of a professional’s judgment.
You should definitely tell your boss and see whether you could be recused from working on the development project.
You should probably tell your father about the situation, depending on your relationship with him. If you did not tell him, and he found out through someone else, how would he feel and react?