Texas Monthly v. Bullock 489 U.S. 1 (1989) was a case brought before the US Supreme Court in November 1988. The case (initiated by the publishers of "Texas Monthly", a well-known general-interest magazine in Texas) was to test the legality of a Texas statute that exempted religious publications from paying state sales tax.
Religious publications had to pay state sales tax in 1988.
There was a law being challenge in 1988-1989 that challenged the exemption law, so it's safe to assume that prior to 1989 the exemption law was in effect. 