Casa Mezcal won’t be open for a few weeks, but buzz is building about the lavish Orchard Street cantina/club/gallery. Last week, Karl Lagerfeld spent six hours there shooting a Chanel catalog. Tuesday, Mexican socialite Alondra de la Parra had Oprah‘s decorator, Nate Berkus, on stage peddling tickets to her Philharmonic Orchestra of the Americas concert on May 11 at Alice Tully Hall. The chic Latinas in attendance were shouting “Olé!” to Carlos Campos on his costumes for New York City Ballet’s production of “Estancia.” Casa Mezcal owner Ignacio “Nacho” Carballido, who has two other neighborhood taquerias, is being called Mexico’s answer to Keith McNally. Some of the glamoratti moved on to Scuderia, where Silvano Marchetto was helping co-owner Fabrizio Sotti celebrate his 35th birthday.