Wicca is a recognized religion. I don't see any problem with them having their own schools and their own meeting places. So long as the schools comply with the same educational requirements and so forth that any other schools have to comply with. And I presume that's what the intent is.
Ummmmm so is it a school for Wiccans, or a Wiccan school? Meaning, is it just like your everyday run of the mill school with math/biology/sports etc that only has Wiccan students so there is no adversity, or is it a school that TEACHES the way of the Goddess? If it's the first one then i'm hoping at least maths will be "how many toads does it take to change a light bulb?" Little bit of Wiccan humour there