Yes, it is the address part of the back that is different. And, not all of the "named" bags have all three different name/address backs. Some are just two and some only the one. It's all just part of their header printing process since they are all the Wichita address - just different company names, abbreviations, etc. Of course, now that they have moved, we will probably see a totally different address so....
It reminds me of the differences in some of the Vitro header where it said "5 Star Brand" instead of "Five Star Brand". A different collectible item.