No. Tips are not included in the dining plan except for the dinner shows, CRT, and in-room dining.
If you are a party of 5 or less on the dining plan, and you are eating anywhere other than the 3 listed places, you figure your own tip. You can pay the tip by cash, credit card, room key linked to credit card, etc. if you wish. I understand that when the bill is presented for signing, it will include suggested tip amounts based on a percentage of the menu price of the meal.
If you are a party of 6 or more on the dining plan, you will be billed for an 18% automatic tip.
(The party size also applies to parties who are NOT using the dining plan - no automatic tip for party of 5 or less, 18% automatically added for 6 or more).
Members of the Disney Dining Experience (not the same thing as the
Disney Dining Plan) have an 18% automatic gratuity added to all their bills at table service and lounges, regardless of their party size.