Seems bombs are bugging out with the infinite ammo as others have said.
I did some testing, didn't buy literally anything or use any of the trainer options except for health until after I got past the bomb making quest and meeting Peri, the bomb seller. I could make all 3 types of bombs no problem whatsoever.
Backed up my saves, loaded back into the game, turned on infinite ammo, BAM, bombs bugged out. Can't craft anymore.
Looks like with the current way infinite ammo works only way to really get more bombs is to buy them, as crafting bugs out.