I've lived in South Louisiana (New Orleans) since 1969, but have never yet made the trip out to that outlying area on Christmas Eve. There's always local TV and newspaper coverage, so I can almost believe that I've had first-hand experience.

(I have seen the bonfire structures in the daylight, days before they would be lit. Pretty amazing work!)

I'm not sure that the custom could be accurately categorized as either "Cajun" or "Creole." It is indigenous to one particular South-Louisiana area, right on the Mississippi River, a little too close to New Orleans to be part of the what's usually defined as "Cajun country." The definition of "Creole" is very ambiguous, but none of the usual meanings (urban New Orleanian of mixed-race heritiage, or rural French-speaking zydeco-playing Black) really apply to the Christmas-bonfire culture of St. James Parish.