If you happened to pass by the Valentino boutique yesterday afternoon, you may have found yourself unable to peruse the designer’s latest creations. A flurry of well-heeled ladies descended upon the Madison Avenue shop yesterday for a luncheon to benefit the Museum of the City of New York. The event marked the kick-off of the museum’s annual Fall bash, New York After Dark, which will be held on October 12th this year. Guests at the luncheon included Tara Rockefeller, Jill Roosevelt, Celerie Kemble, Dayssi Olarte de Kanavos, Allison Aston, Alexandra Lebenthal and Helen Lee Schifter.