The Mayflower Madam, Sydney Biddle Barrows, the Pilgrim descendant who gained notoriety as former boss of an exclusive call-girl service, has married Darnay Hoffman, a legal historian and television producer--in a formal church wedding. The music was by Handel. A miniature bride and groom topped the four-tier wedding cake. An Episcopal canon was chosen to perform the ceremony. Barrows pleaded guilty in 1985 to a misdemeanor charge of promoting prostitution.