Guideline 4.3 is pretty explicit: Don’t create multiple Bundle IDs of the same app. If your app has different versions for specific locations, sports teams, universities, etc., consider submitting a single app and provide the variations using in-app purchase. That seem to be precisely your case. Another thought: I don't know if it is the cause, but there is a Babbel app to train for foreign languages. The name of your app appears pretty close to it.
Topic:
App Store Distribution & Marketing
SubTopic:
App Review