Having made ~40 wrought iron with iron ochre at your set of skills:
Average bars/smelter is 2-3, average bloom per bar is ~60%, average wrought per bloom is 50%.
You should be getting roughly 1/2 wrought bar per smelter of ochre, a little more. If you're getting less, bad luck. Doesn't include the cast you generate from failed bloom>wrought.
Are you letting your bloom sit? Someone told me it'll eventually turn to slag if you leave it alone, but I've yet to confirm that personally.