Of course there is an entire forum here on Permies regarding strawbale:
strawbale forum
Straw bale is natural fiber that is slow to decompose, compressed to a very high density to form block used to infill a structural frame. Bales themselves can be made to be load bearing if compressed tight enough; but most builders just use it as a super insulation inside a timber frame (or concrete in your case.) The bales can be coated with cob, plaster, or any other material that will adhere to the bale to form attractive, well insulated natural material wall. The advantage in your case would be less clay needed to prepare to make a solid cob wall, a higher R value, and quicker build time.
I don't think you would have any issue with cracking of cob with rebar installed. As you know cob walls are thick. An additional 1/2 of rebar won't impact the material.
A few links for strawbale:
webpage
webpage
Are you planning to build in the Austin area or Texas in general? I think Austin is more alt. building friendly than most places for permits and inspection, but definitely check with code enforcement before you get too far into your project.