I’m aware that there is already a thread about this from december last year. However it is marked as having a solution even though it clearly is a bug and is still present in the game. Since I’d actually really like to be able to do this craft I decided to bump the topic seeing as it might get forgotten otherwise. I hope it’s not too much of a bother.
The shard for ‘Chance to shred armour on hit’ says it can be applied to bows. But when you actually try to put it onto a bow it doesn’t show up in the list of available affixes.