After you did ##72786# reset, it should have rebooted the phone, then it should have performed hands free activation, then performed update profile and prl.
If some of these didn't complete then your data might not work. If your 3g was done, there is the possibility the infrastructure to perform those updates was also down.
You can perform update profile from menu->settings->system updates or menu->settings->about phone->system updates
Also if you were on an older PRL, it may have updated you to a newer PRL. This might have removed (or added) some roaming capabilities.
I would just try the ##72786# reset again now that the Sprint network in your area is back up.
Disclaimer: No touchscreens
were harmed nor injured during the creation of this post. GPS
units were all treated ethically and humanely.
Signed: People against misbehaving Nexus 7 2013s