Once they are growing well, if you wish to force them to grow faster and taller than their usual 2 inches a year, bend down the branches lower than the growing tip. As for your request on B. buceras, although it is listed in several of my books, the specific information is sketchy at best. All give general descriptions of the tree but there's no information concerning light requirements, etc. Here're my gleanings from several books. It is tender but will withstand some frost.
Propagation is from cutting as seeds are dificult to germinate.
Leaves persistent, bluish-green above and yellowish green below. Hope that helps. As always, you may use any or all of this in the TOW posting, or elsewhere as you see fit. Ken Devos Ft. My info came from an article in our state bonsai organization's quarterly publication.