A beak-nosed comic actor with an improvisational background, Peter Bonerz went from playing Jerry the dentist pal on "The Bob Newhart Show" (CBS, 1972-78) to directing episodes of the series and then developed into one of the more prolific sitcom directors of the 1980s and 90s. Bonerz first acted on stage in a production of "Agamemnon" at Columbia University in 1961, then made his Off-Broadway debut doing an improvisational character in "The Premise" (1962). He left New York and between 1963 and 1969 appeared with "The Committee", a revered San Francisco improv troupe. When he returned to