Tips

[Sunshine1010]

Can tips be put on your card (the pass card with the dining plan on it?)

Can tips be put on your Rewards card?

[disneymom2000]

I would think so, since your passcard is connected to a credit source. At the end, it should show on your final bill they put under your door before you check out.

[DDuck66]

Yes two both questions, as long as you have had Guest Relations add charging privileges to your card. If you are going this year, the tip is still part of the dining plan. In 08, tip is not included.
As for the Rewards Card, as long as the restaurant accepts the card, then you can add the tip. Some restaurants do not accept the rewards card. I believe it is some of the non disney owned restaurants.