Wirelessly posted (BlackBerry: BlackBerry8530/5.0.0.1030 Profile/MIDP-2.1 Configuration/CLDC-1.1 VendorID/417)
If US is selling this connection as a single ticket, then presumably US has determined that it is "doable." But not every doable connection will be made, due to factors like delay of the incoming flight, delays at immigration and customs, etc.
If you should mis-connect on a single ticket, US will accommodate you on the next available PHL-TPA flight.
Are you traveling on a single ticket? Are you traveling with checked baggage?