I'm not sure the NFO is right, it should be the version of Sonic Advance in the other multipacks, which is indeed just a 1.1.
The title screen (pictured in the OP) just has the game listed as Sonic Advance (Same logo on Sonic Advance's title screen).
Maybe it's something like "Sonic Advance plus Sonic Battle" and they screwed around with it in the NFO.
Aside from the NFO, there's little reason to call it Sonic Advance plus. That would be like pSyDS calling their dump Super Mario Bros. 4.
edit: There's no playable difference from this version and the original. SInce it's at a different point in the ROM, comparing is n good, as the pointers etc are off.