Couldn't you do something like this instead of doing a second database query?
PHP Code:
/*Create variables*/
$VARIABLE_1 = "123";
$VARIABLE_2 = "ABC";
/*Register variables in first template*/
vB_Template::preRegister('TEMPLATE_1', array('VARIABE_NAME_1' => $VARIABLE_1, 'VARIABE_NAME_2' => $VARIABLE_2));
/*Register variables in second template*/
vB_Template::preRegister('TEMPLATE_2', array('VARIABE_NAME_1' => $VARIABLE_1, 'VARIABE_NAME_2' => $VARIABLE_2));