Time manipulation has never been proven and it is likely non existant. If it were possible it would most likely be limited to a very small amount of time dilation since the brain must calculate more in a shorter amount of time.
Example
If we normally dream at 24 images per second, and one hour in dream time takes one hour in real life

If were to dilate time in the dream by two times our brain would have to calculate 2 hours of dream in one hour of real life, requiring 48 images per second.

I think what most people witness as time manipulation is just the logical side of the brain filling in gaps of the dream to give the sensation of a longer dream.