The Photo Stream is designed to push your images into the cloud the moment they are taken. It does not (yet) support to show the ratings and most of the tags.
If you have an event with all photos you want to keep, the easiest way would be to delete all photos from the Photo Stream (on all your IOS devices) and then add only your selected "keeper" images to the Photo Stream again.
Added: It is not safe to rely on the Photo Stream for storage, since it will only keep a snapshot of currently added photos - the last month's photos or the last 1000 photos. You have have no control over the sorting of photos in the stream or how long they will be kept. The Photo Stream is a means of sharing, not of storing images. I prefer to use "Shared Photo Streams" for more permanent photo selections. These will show exactly the selection of images I add to them, and they are not automatically erased after a month.