One story that I heard about them finally getting the IRS label, is that John Travolta told Bill Clinton that he'd go easy on the BC character in some movie if he'd convince the IRS to give them the religion tax id...
Around the same time, give or take, Germany bestowed the "Cult" classification on the organization.
The movie was “Primary Colors”, based on the book of the same name by “Anonymous” (but really Joe Klein).
I do think that the book was harder on Clinton (or the character who was based on Clinton) than the movie was. Been a while since I saw/read either.