Agree with Lee. Although in the US we're more or less obligated to leave 20% as the Standard for good service, with 10% or less indicating poor service, 10% here as the standard is fine, but if you have a very enjoyable experience and are pleased by the level of service, then by all means you should tip more! It gives servers an incentive to do their best, which improves overall quality of the dining experience. I'm sure they don't grow to *expect* more and that when they get it is a nice surprise. What's wrong with that? Especially in this country when surly/poor service is the norm. It is the choice of the patron.
For the original question, NO the cubierto is not included in the tip but supposedly goes to cover bread, etc., that they might bring to the table. don't like the concept myself, but it is what it is.