"Books are to be called for and supplied on the assumption that the process of reading is not a half-sleep; but in the highest sense an exercise, a gymnastic struggle; that the reader is to do something for himself."
Unfortunately, adding regions/provinces is beyond the capabilities of the ordinary volunteer region managers - it is too high in the hierarchy, so to speak. We can only add cities and release zones like any other Bookcrosser can when they make release notes. Something like this will need to be referred to Support.
As for adding cities, nothing can be done until Metro Manila is added as a province. And, even then, you can do it yourself as you release books. As you progress through the release process, there will be an option to "add a city". It's quite easy to do and, as a local, you will be better positioned to check correct spelling etc. It's not something easily done by a foreigner with no local knowledge!