It’s pretty much guaranteed, though there are different kinds of symbiosis I suspect you specifically mean mutualism where both creatures benefit. Small birds removes parasites from larger creatures today and there’s no reason to believe this didn’t happen prior to the extinction. The Jurassic World giganotosaurus teeth cleaning(probably inspired by this piece) is also very likely.

There’s also symbiosis like commensialism where one creature benefits and one is not affected like this beetle that lived in dinosaur nests and fed on detached dinosaur feathers.