The main problem with the original code is that it does not properly (as in it doesn't do it at all) insert the blog name or tag line. The code below inserts the image into the block created by %image:
HTML Code:
<?php if( is_page('29') ) {
$HeaderURL="http://www.shantayoga.com/wp-content/themes/shanta/images/header/header.jpg";
$CustomHeaderImage = 1;
} elseif ( is_page('22') ) {
$HeaderURL="http://www.shantayoga.com/wp-content/themes/shanta/images/header/header-nidra.jpg";
$CustomHeaderImage = 1;
} else {
$CustomHeaderImage = 0;
} ?>
<?php if( $CustomHeaderImage == 1 ) { ?>
<div id="imagecontainer" class="header-image-container" style="background: url('<?php echo $HeaderURL; ?>') top center no-repeat;">
<div class="clickable"><a class="divclick" title="Shanta Yoga" href ="http://www.shantayoga.com/"> </a></div>
<div class="titleoverlay"><h2 class="blogtitle"><a href="http://www.shantayoga.com/">Shanta Yoga</a></h2>
<p class="tagline">Live with Ease</p></div></div>
<?php } else { ?>
%image
<?php } ?>