I'd allow it. I'd just rule that it covers one type of bomb. I'd rule the same with for Favoured Gear: Spear. As long as you buy the exact same Superior Dwarven Bomb, then it'll work for it just fine at my table.
That's how I'm leaning too. It makes sense in terms of character, though it might stretch the rule a bit.
I can't see it being a power issue either - throw your last one and you have a dead feat until you get more of them (unlike a melee weapon). Plus has the bonus of not making it an utterly useless feat for thrown weapon users.