You almost answered your own question. By coming here to this forum to check, you realized that this forum is probably one of the most current sources to see if something was going on at specific sites. So you could check the specific discussion threads for each of those Superchargers you are asking about.
As far as finding them, it may sound a little roundabout, but I go to the map at
www.supercharge.info because it's easy to find the city and click the Supercharger dot. Then click "discuss". That links right to the thread for that Supercharger. In your case:
Supercharger - Tifton, GA
Supercharger - Macon, GA
And since you did the legwork to check them out, it would be really helpful to add that info to those forum threads to let others know.