Peter - It's so hard to compare the two, one you catch in rivers, one in flats, I know they both fight great though. I would rather catch bonefish then steelhead, that I am sure of. Bonefishing is like a combo of hunting and fishing, so rewarding to see a fish, stalk it, then execute the cast, retrieve, and hookset.
I was with a fishing buddy and his family, we did 1 day guided bonefishing, 1 day guided bluewater, rest of the time it was DIY. When we fish together we often get split up, you don't want to wave your friend over from 1/2 mile away just to take a pic for you. Plenty of fish to be had on your own if you have a rental car and the knack for doing some exploring.