a couple things I remember about the Union apps... you need to have your CDL , birth certificate, and if they call for you to go to work for someone.. you go to work for them. You dont get to choose. That is what I gathered from the questions i have asked previously. ( I am sure there will be trolls here to correct me on anything I mis-state )
We are a union shop here, but they hire outside of and have their own apprenticeship program outside of the union.