An accdb file is not by itself bit-specific, only if you have coded API calls specifically for 32 or 64 bit, which you normally wouldn't do.
"Removing PtrSafe" makes only sense if you run Access 2007.
Thus, an accdb file (or renamed to accdr) as is will run in 32-bit Office as well as in 64-bit Office.
However, if you compile the file to an accde file, this must be done using the same bitnes of Access as that installed at the intended users.
Thus, if you have both users running 32-bit Access and users running 64-bit Access, you must create both a 32-bit and a 64-bit accde file.