Google's local index is told to update every 30-60 days, and in practice, that seems about right. Maybe a little closer to 60-90 though. Unlike organic, you can't build a link today and expect to see movement in the serps. Won't happen. As I understand it, if the directory is worth its weight, Google will index it quickly. From there, it seems like it sits in a Q, waiting for the next index update before being credited to your listing. So ya, patience. But don't sit on your ass, be building quality inbound links, gathering reviews, and building more citations. Good luck!