Because Santorum’s “suspension” was late in the game it’s quite likely that information got passed on. When I was a Reagan alt delegate in Illinois the ballot had the names of the delegates and who they were pledged to alongside in (paranthesis). I don’t know about all the 50 but most states the delegate elected is committed to his pledge on the 1st vote and that usually goes to the candidate who carried the district
When I lived in PA (Not since ‘88), all that appeared on the ballot was the name of the delegate, without saying which candidate the delegate was committed to (if any). However it appears it is still that way.
Sunday 10 June 2012: Summer Meeting. The Pennsylvania Republican State Committee will meet to choose 10 at-large delegates.
The at-large delegates, chosen by the state’s Republican State Committee, will go to the Republican National Convention officially “Unpledged”. [Rule 8.3] In addition, 3 party leaders, the National Committeeman, the National Committeewoman, and the chairman of the Pennsylvania’s Republican Party, will attend the convention as unpledged delegates by virtue of their position.