You can get free shipping as long as the item is paid partially with the red card
I was unable to get it to work.
For example, the purchase is $8, my saved GC is $300. My saved Red Card has $60 balance.
When I check my Red card and my GC to pay for the order, total amount is charged on my GC and thus no free shipping. It used to be you get charged $5.99 on GC and 1 cent is charged on Red Card and I got free shipping.