You may not be aware but, with a recent iOS update, Apple replaced the built-in Google Maps app with their own Maps app. There were a lot of complaints about the new Maps, which included places missing or wrongly located.
You can't get an improved level of detail if it isn't in the maps in the first place. We just have to hope that Apple get this problem sorted sooner rather than later. Incidentally, iOS 6.1 was released within the last few days, but I don't know if this included an update of the Maps.