I was getting AT&T voice and cellular data (NOT roaming..that was turned off) at all those locations, with no extra charges. I even logged into my AT&T account at one point to make sure.
My son has T-Mobile, so he had zero access the whole trip, but I brought my business AT&T hotspot and set it up in the cockpit when able to connect to AT&T so he would stop getting the "I can't communicate with my friends!" shakes. <img src="http://www.traveltalkonline.com/forums/images/graemlins/Yikes.gif" alt="" />