I'm afraid not. The behavior of any one text animation is
purely the "domain" of that animation's design. Most are intended
as short "headline" styles or such, so it's understandable that
their authors didn't accomodate text wrapping.
Captivate itself does little other than provide the means for
configuring basic parameters such as the character string, colors,
font, etc. How the text is animated (including placement/wrap) is
defined by the logic of the text animation clip.
Unless you find and install or custom-build a text animation
that does what you need, you'll be out of luck in this
regard.