If you modify your Super Bombs count by 1 using the Link Data cheat in ZC, your Bombs increase by 4 and your Super Bombs increase by 1 in addition to how many you gave yourself in the first place.
EDIT: You don't even need to touch the Super Bombs field; This happens whenever you enter the Link Data screen, and I assume, have Super Bombs. FYI my Max Bombs were set to 99 and I had everything, except the Infinite-items and Letter(used).
Also I might as well report that if you use A+B style items and equip both the Super Bombs and Bombs and use up all your Super Bombs, your Super Bomb button might revert to normal bombs (at least on the subscreen I was using)... so you have both buttons equipped with bombs.