DM,
I can't answer the OPs questions, as my card isn't issued by Wells Fargo. I do know that if you want to use the gas station after hours then you must have a chip-and-pin card that works with the automated pump. If the pump doesn't recognize the chip in the card then it won't work at all, just as it won't work for non-chip cards.
My understanding of the OPs question is that there is a concern that if the automated pump does not work with the Wells Fargo card then a signature is required, meaning the card can only be used when the gas station is open and the attendant is there.
I've also used my card in SBH restaurants. My card is placed in the handheld credit card machine, the waiter enters the charge amount, and the machine is presented to me. I enter my PIN, and a receipt prints. If my card's chip were not recognised then the card could be swiped, and a slip would be printed for my signature.