I posted on your other thread, but wanted to show you a link. The cases reported are usually those where the dog ate quite a few, but that doesn't mean a lesser quantity is safe.
Are Grapes and Raisins Really Toxic?
The lowest estimated toxic dose here is 10-12 grapes for a 20 pound dog. That is 1 grape for every two pounds. So an average size Yorkie would need to eat 2-3 grapes to cause concern (generally). Raisins are more concentrated than grapes. So yes, vomiting should have been induced.
Ellie has had many raisins before I knew better. Never caused a problem. Not all dogs react to them. But if it were to happen now, vomiting would be induced. If I couldn't get to her in time, an ER vet would be contacted and asked to look up the toxic amount in their toxicology textbook. JMO.