can one access Component value from Wordpress plugin onAfterRender ? If so , how do you get it done ? I'm using Joomla 1.5.

$this->assign('name', 'John');

This line just passes the string 'John' in the view towards the layout, it's nothing related to any wordpress plugin. Should you work onnAfterRender and wish to get certain info in the page going to be shown, you could attempt search for this with the renderd content, ehich could be utilized using

JResponse::getBody();

if you wish to replace some information on the page, do this and, in the finish from the wordpress plugin, "rewrite" the page

JResponse::setBody($yourData);