The bubbles of carbon dioxide gas “stick” to the raisins and help carry the raisins up to the surface. When they reach the surface, the bubbles disappear and the raisins lose the “support” of the bubbles and sink to the bottom of the liquid, as the raisins are denser than the amount of water displaced.
Try this experiment with different types of acids and see if it works in the same way as it does when vinegar is used. You could try lime juice, apple cider and other “sour” liquids.
Vinegar and baking soda are often used to unclog sinks and drains, as the reaction that is produced helps to loosen up the clogged dirt. They are also used on their own, to help in household cleaning.