They have updated the wording in our favor:
https://www.delta.com/us/en/booking-...n-certificates
Beginning April 6, 2017, Medallion Members traveling with one companion will be eligible for Complimentary Upgrades to both First Class and Delta Comfort+® based on the Status of the higher-tiered Member, as long as the companion is a General SkyMiles Member, Medallion Member or partner airline elite member, traveling in the same reservation. Tickets are eligible for Global or Regional Upgrade Certificates but are not eligible for mileage upgrades.