NEW YORK — Among the many well-turned- out guests from across the country at the San Francisco Ballet’s Opening Night Celebration at Lincoln Center Tuesday night, Vera Wang proved a graceful ambassador for the event’s host city. Clad in a black crepe de chine balloon dress with a wool felt corsage from her fall collection and wearing her own jewelry, the former ballet dancer was there at the behest of old friend and co-chair of the event Pamela Joyner to welcome the company back to Lincoln Center for the first time since 1993. “She’s a force to be reckoned with,” joked the designer of Joyner, noting the two met at a trunk show in San Francisco years ago. As for the Californians, they displayed some charmingly tourist-like impulses during their stay in the Big Apple. One ballet supporter was so excited to find out that her hotel, the St. Regis, was close to the “Today Show” that she bolted from bed to catch a taping. “I was this close to Matt Lauer,” she boasted during cocktails on the Promenade.