We would like to refer you to a writing tip the community offers about 'dream' stories. While this week's prompt does invite writers to address day dreaming as a topic, that is not an invitation to use what is called the "It Was All A Dream" escape hatch. Unfortunately, this story falls into the trap.
The story reads well. Readers feel it's rather exciting, getting that promotion. They want to know what happened. Then you tell them they basically wasted their time because, It was all a dream. As good as your writing was up to that point, readers are disappointed.