Bernadette Peters is a Catholic and a convert to Scientology. We have not yet compiled current information about her status and activity in either denomination.
From: Tilman Hausherr, scientology celebrities FAQ" of alt.religion.scientology, last updated 1 July 2005 (http://home.snafu.de/tilman/faq-you/celeb.txt; viewed 11 November 2005):
4.8.1996: Added Bernadette Peters [to this FAQ]
Name: Bernadette Peters
Status [in Scientology]: [uncertain]
Achievement: Silent Movie; The Jerk; Pink Cadillac
Sources [confirming that she was/is in Scientology]: The Bergen Record 3.10.1985