Of course dogs have taste buds... Why else would they rather have your hamburger than they're kibble... Or know what to eat at all for that matter.
 
As in humans (but to a greater extent), their "taste" of food is filtered through and enhanced by their sense of smell... But if you've ever tried to give a dog a bitter pill that has no odor association, you'll know without a doubt that they have taste buds too!

 Dogs definitely can tell the difference between something that smells better to eat than another thing. My dogs have some treats that they like okay, and then they have other treats they go bonkers for. They love the peanut butter flavored treats better for some reason.

 Dogs have fewer taste buds than we do, but they more than make up for it with their sense of smell.  The two senses are closely related, even for us.  Have you noticed how things are less "tasty" when your nose is blocked up with a cold?