No, the C's defensive strengths matchup extremely well against the Bulls' offensive strengths and will consequently do a good job limiting Chicago in a playoff series.
The main defensive strengths being their defense against ball-dominant perimeter players, especially their pick and roll defense, their length and shot-blocking on the interior against dribble penetration, their PG defense with Rondo, and Garnett's defensive skill-set against Carlos Boozer.
The Bulls are a very good team but they are not quite a title contender yet. They have the core of their squad in place but their supporting cast (mainly their non-Deng wings = Bogans, Korver, R.Brewer) don't complement their star talent as well as they need to. So they are a year or two away from fixing that flaw and becoming a full fledged title contender.