The other side of the coin is that there really might not be any actual pattern to pull out of any single dolphin's vocalizations.

Just because dolphins possess a possible capacity for language doesn't mean that any language exists.

I'd figure the mutlitude of dolphins in the wild all establish personal colloquial parlances, organized according to the whims an experiences of each individual pod.

Kind of like in that movie Nell, where the children grew up learning to make noises like their stroke-afflicted mother. If there are no regimented social constraints to enforce teaching and learning, wild animals have no externalized motive for establishing the codified norms of a symbolic language.