Not sure on spouses officially but parents travel at S4 on all metal on DL. They also cannot be tied to the employees reservation because of the priority differences so they need to be on a separate one if traveling with you. They also get a seniority date as the "date of travel" so that with the yield fare gives them basically the worst benefits for flying on Delta. I have had to contact employee travel for a lot of issues with them and that is what they get for their priority regardless of metal... Pretty bad. They said they are welcoming comments right now to pass on to those who negotiate so feel free to email them about it. Not sure how much good it would do but oh well.