It all depends upon how closely you interpret the word "dynasty." I'd have a more difficult time calling them a dynasty due to the fact that there was a four year span from their first championship (1999) to their second (2003). Certainly, they could rightly be considered to be called, along with the 2000-2002 Lakers, one of the best teams of the past 10 years.

Look at the Patriots in the NFL. You could argue their case as a dynasty much more because they've won 3 Super Bowls in the past 4 seasons.