This petition was rejected

The Government e-Petitions Team gave the following reason:

We cannot accept your petition because the claim that prayer rooms create an exemption from council tax has no basis in council tax law. It is not possible for owners of domestic property to avoid council tax by claiming that their property, or part of it, is used for religious purposes. There are circumstances in which religious practice can give rise to council tax discounts, but the use of domestic property for communal worship is not one of these.

We're therefore not sure what further action you'd like the Government or Parliament to take.