How do i reference the theme path in pages for images?

Use get_template_directory_uri()

print get_template_directory_uri() . '/image.jpg';

In child themes use get_stylesheet_directory_uri() if you have replaced the image.

In a shortcode this would look like this:

<?php
/* Plugin Name: Theme URI Shortcode */

add_shortcode('theme_uri', 'wpse_66026_theme_uri_shortcode' );

function wpse_66026_theme_uri_shortcode( $attrs = array (), $content="" )
{
    $theme_uri = is_child_theme()
        ? get_stylesheet_directory_uri()
        : get_template_directory_uri();

    return trailingslashit( $theme_uri );
}