Originally Posted by
octr202
No, you cannot use the upgrade coupon with a companion coupon.
I believe you can (in theory) upgrade the companion ticket with cash, and then use the upgrade coupon for the paid ticket, but not sure how easy it will be to pull off that level of gymnastics. Also, expect the upgrade charge for the free ticket to be pretty substantial. As my Amtrak travel is on my own dime, I've never done it.
OCT202 is correct; I did it once, back when the "accommodation fee" was ~$70. It takes a good phone agent to do it.