Dyeing a Ball Dress with Bleach Stains?

I have a white ball dress that was used by a family member before me, it's absolutely stunning. Unfortunately it had a few food stains on the bottom so my mother tried to bleach it. It stained it yellow so we decided to dye it a metallic grey.

The dress looks even better, but the stains are a lighter colour giving it actually a nice dip dye affect, but there are some darker patches on the bottom which I think are the normal dress, should I re-dye or use vinegar?

By Beth HD