I have a couple of questions....were these fish bright? And were they coming completely out of the water or just porpoising? I'm assuming there was no obvious reason to explain why they were jumping.

I've seen steelhead thrash the water when they are actively moving upriver, in which case they can be finicky (often times more intent on moving than establishing territory is how I read it).
I also have seen numerous steelhead jump repeatedly trying to shake a broken off rig that they hammered. In which case I have had no luck getting them interested in anything.
This sounds to me like just another steelhead puzzle. (The only thing you can say for sure about steelhead is that you can't say anything for sure.)