It takes about two weeks to learn your travel patterns. I've been using iOS 7 since day 1 of beta 1. The first time, it took 3 weeks to appear. Then I had to restore my phone. After that, it took 2 weeks to appear again.
Next destination is something your phone will learn after a couple of weeks once it figures out your travel patterns.
Give it another week or so, it needs to make sure that one week was not an anomaly.