I've never read or heard confirmation from Sam Raimi or the producers that the scene was supposed to be in the actual film. It doesn't seem to fit in the film, not the content, but the style of the robbery and web catch. It seems to be shot differently. It has such a different look and feeel that the actual film.
Also, why put that entire sequence in the film? If we already saw it, and know the surprise of the giant web, why show it again. They rarely if ever show an entire sequence in a trailer. It seems to me that it was made just for the trailer. They put the shot of Spider-Man from that trailer in the film simply because it was a short shot and it looked great. Ironically, even that shot looks somehow different from the rest of the film.
I'd like to see direct confirmation from someone involved in the film.