You only get the bonus if you shatter an equipment on a friendly champion. But you are correct by the letter of the ability that should work.
Bumping this as it's still the case - the bonus is gained only if you shatter an equip on a friendly champion, instead of obtaining it upon shattering a friendly equip.
Sorry to necro but I encountered this bug today and I was wondering if maybe the description of the ability could be changed to reflect the actual way it works in the game. I just want to avoid getting surprised in a match. I get the bonus if I Shatter an equipment on a friendly champion, regardless of who is the owner of that equipment.