I'm curious if anyone has ever purchased two tickets and used the Bank of America Alaska Visa Signature $50 companion ticket and then upgraded the tickets with the Gold Guest Upgrade certificates.

I have my last $50 companion ticket before it switches to the $99 companion ticket and it expires soon so I need to get something ticketed asap.

From the Bank of America Companion Certificate terms it says the following:

Combinability: Not valid with any other discounts, including Discount Codes, My Account online discount, coupons, discount programs or other arrangements.

Mileage Plan: Mileage Plan credit applies and upgrades are allowed.

I'm not sure what to take from this. When it says upgrades are allowed is it referring to a automatic upgrade, or a certificate upgrade, a mileage upgrade, etc...?
It says no coupons so I don't know if that would disqualify me from using the gold guest upgrade certificates.

I tried a search but couldn't find anything that answered this.