Does vision and mission start from the top or the bottom?

Sure from the Top which is matching with the company goals :

http://www.slideshare.net/daveaddy/vision-and-mission-statements-a-set-of-criteria-for-development-and-evaluation

The Vision is meant where an organization wanted to be or ultimate achievement

The Mission is mean why an Organization exist in economic activities

therefore Vision and mission start from Top but I will flow to bottom to achieve its purpose