The KLM website reports that your flight arrived with a delay of 3 hours and 34 minutes. As such, you arrived 26 minutes before the flight would even come into consideration for EC261/2004 delay compensation; however, given the weather delays yesterday, it is doubtful that that would even apply. [That the cargo/luggage was still being loaded hours past departure doesn't necessarily indicate that that was the reason for the delay; it could just be that they decided to load up delayed transfer baggage and/or cargo in the knowledge that the plane wouldn't be pushing back for a considerable delay after the scheduled time of departure]
By all means, lodge a complaint if you wish, but temper your expectations. You are one of the lucky few to get where you wanted to be yesterday. Things have deteriorated a lot at AMS since you left....it's coming down thick and fast now.