The “Save the Garment Center” giveaway T-shirts at Anna Sui said it loud: New York’s garment center is very much her cause. But the delightful message she sent down her runway was pure Mexico. Beaded and embroidered shift dresses, pom-pom tops, peasant shirts, circle skirts with florals, fringe and every color in the rainbow — it was a parade of fiestawear, all of it young and fresh. Sui gave the lineup a Fifties flavor with retro bikini tops, pedal pushers styled up in a matador motif and fit-and-flare silhouettes. Yet for all the trimmings and trappings, it was more polished than in the past, and as true to Sui’s boho rock aesthetic as it was a festive riff on folky, south of the border fun. Olé!