There are a few names for the region I live in now, the most oft-repeated being “Central Georgia” or “Middle Georgia”, and I guess this area would include Macon, Warner Robins, and Perry, with all the smaller towns in between, along I-75. Macon is called Maconga by dorks like my dad.
Atlanta gets called Hotlanta, another one of those tourism marketing names that gets on all the native’s nerves. I have never really heard people use any other names for the area, but that’s considering that when they say ‘Atlanta’, they could mean the city itself or any one of dozens of smaller cities that encircle it.