Dracaena Warnekii Blooms

I received this plant in 1996. A greenhouse owner across the street at the time told me what it was and asked me if it had bloomed? It has. but only once in 17 years. What kind of plant is this and what can I do to get it to bloom again? The bloom was a 9″ “stick” which came from the top and had small flowers all over it which were very aromatic. Then the blooms fell off and so did the stick. Any help would be appreciated.