Question about placing calls and how they are connected

I have been using Google Voice's web app for the past month or so, and haven't had any problems or concerns. When I noticed Voice Central was available today I was excited to try it out! There seems to be one obvious difference in the way that calls are placed. When I use Google Voice's web app, and place a call, I get a call back from some local Google number in my area. When I use Voice Central to place a call, I get a call back from my own Google Voice number. I guess the root of my question is as long as I have my Google Voice number added to AT&T's "A-List" then the call should be free regardless? To anyone unfamiliar, AT&T's A-List allows free unlimited calling to any 5 numbers of your choosing. Prior to using Voice Central I simply added that local "Google number" to my A-List which allowed me to place a call at anytime for free.