Citi Cash Back Plus - anyone tried to use it for Shell fuel? How is it?

I understand that the original Citi Cash Back card gives 20.88% savings on fuel, and other Citi cards receive 14% savings. I am unable to find any information about Cash Back Plus and fuel savings online, it seems as though Citibank did not update their website on this. With the Cash Back Plus card being new, does it qualify under "other Citi cards"? Has anyone tried using the card for fuel so far?