Pinthouse Pizza, the popular new brewhouse and eatery on Burnet Road, is looking south to expand. As first reported in the latest Austin Beer Guide magazine, and later by Austin 360, Pinthouse is going to open a second location in South Austin. Pinthouse Pizza's Burnet Road location on any given night is crammed with lovers of pizza and beer sitting shoulder to shoulder - often with countless young children scampering about. According to the guidebook, owner Ryan Van Biene plans to open the…