OCB is a split card, attack/action.
Chun- Li's R Commit : After your opponent's second form during their turn resolves, you may play 1 non-action form from your hand as a form.
So the question is:
Can I use Omnidirectional Cluster Bomb with Chun-Li's R?
I would think no, becuase no matter what, it is always an action card.
This was answered in a previous thread that you could play a split card using her R, you just can't play the action side.
As covered previously, she says play one non-action, not one non-action CARD, so as long as she's playing the attack side, she can play ClusterBomb.
It's kinda funny, there was a fairly lengthy thread on exactly this topic a week or two ago.