Not necessarily. Most places have 10% for DVC, 10% for AP and 20% for TIW.
Initially, when I got the TIW, I was questioning the value/wisdom, because they give you 20% off, but an automatic 18% tip, so essentially it's 2%. I despise the concept of an automatic tip when the person may do a horrible job. Then someone mentioned you're going to tip anyway (and I typically tip 20% or more). I suppose if the person does a horrible job where I wouldn't leave a good tip, I can simply talk to the manager. Fortunately, there has only been one instance on Disney property where I wanted to leave a poor tip.