Consuming enough of any food can cause a feeling of bloating, though there is nothing about grapes that suggest they cause this sensation more or less than any other type of food. The key to avoid a feeling of being bloated is simply to avoid eating too many at once.
There are certain types of foods which people claim cause them to bloat, though it is usually due to the fact that they eat too much of it at one time. The fact is that grapes are actually great for your body because they contain lots of vitamin C as well as vitamin K and potassium which is important for your body.