You'll need your driver's license along with the TiW card.
From the TiW page on the DisneyWorld website:On our last trip a cast member at Mama Melrose did balk when I gave her 3 credit cards for the bill. We typically use the tables card and split the bill down the middle. We don't separate the check by the order but just split it evenly. One other cast member at Be Our Guest for dinner said its a "Grey area" since we arn't typically asking them to separate the check.