Use code VIBCHIC at checkout if you're shopping online to get 15% off your purchase. And don't forget, EBATES has 8% back at Sephora as well as a list of all the Sephora coupons and gifts with purchase.
This states it's available only for Sephora VIBs. I have no idea if there is that much logic in their shopping cart system to actually cross reference codes with VIB status. If you want to use it in store, I believe you to have the little bar coded coupon that came with the flier.
Hope this helps someone!