As of today's release of iOS 6, iOS no longer has a Google Maps-based maps app built in. However, the best-fitting maps tag I could find for iOS is google-maps. Should there be a separate apple-maps? Or should the existing tag be migrated to something more generic, maybe maps.app?
This is a level of specificity that doesn't need to exist for tags. I would have no problems adding a synonym for all the tags you mentioned in your post to simply maps.
The detail goes in the question, the (broad) classification goes in the tags.