Thanks MK. OK, I understand that unless the departure originated from AGS, they cannot offer flight following or advisories to flights from another airport. It just seems strange for say, two planes to be in relative close proximity to each other (practice area) and one be advised from an airport 20 NM away and the other from an airport 120 NM away.
I now see why I only hear traffic advisories for one airplane and not the other.
As a side note, at AGS, if you depart north 35, you are in ATL coverage, if you depart south 17 and maintain runway heading for a couple minutes you are in JAX airspace.
Thanks again for your reply.