How do I pass WordPress’s get_bloginfo(‘siteurl’) to Jquery?

Use wp_localize_script() to pass variables to the front end so that you can pick them by javascript.

Use it like this:

wp_enqueue_script( 'some_handle' );
$data = array( 'some_string' => __( 'Some string to translate' ) );
wp_localize_script( 'some_handle', 'object_name', $data );

And pick it up like object_name.some_string in javascript code.