Well the question we are concerned about is whether evolution is or is not science. And it seems to me that scientists are a valid authority on that question (indeed, given the "demarcation problem" it is reasonable to argue that the judgement of a clear majority of mainstream scientists is a valid criterion - perhaps the only valid criterion).
What would constitute a similar question for priests ? Presumably it would be on matters of doctrine, and I think that if a large church of priests over a long period of time agree that their church holds to a particular doctrine then it would indeed be valid to agree that their church did indeed hold that doctrine.
Note that neither question deals with the truth of either a scientific theory or of a religious doctrine.