Does Pyrotechnics work with Heavy Artillery?

[Fatmagic]

Does the 200% damage bonus apply to the 150 damage that Pyrotechnics deals?

Wondering if combining the two with Cluster Bombs, Efficiency, and 6p Manticore set will be enough to make Bombs a serviceable weapon in DM+. If it works the way it says, I would have something like 5-6 of each damage-type bomb (Grapeshot, Dancing Star, etc, depending on if Heavy Artillery rounds your bomb total up or down) and 10 each of the non-damaging ones like Northern Wind, but they'd still deal 450 damage from each fragment of Cluster Bomb?

And this is assuming that Pyrotechnics damage doesn't cancel out the effects of bombs like Northern Wind.