Vera Wang was guest of honor at Zac Posen‘s party for his Z Spoke show — sparking speculation they may soon collabo rate together. Wang was spotted chatting to Zac and his mom, Susan Posen, who returned to head his fashion house last October, at new Mid town hot spot Lavo on Sunday night. Zac told us: “I feel like I am going in the right direction, I’m ex cited about showing in Paris . . . I am working round the clock.” As for collaborating with Wang, a Zac rep said: “Zac and Vera are good friends who sup port each other’s successes. Nothing more than that.”