There is a easy way to get zend framework 2 base path with domain name in layout.

1. In layout.phtml

$homeUrl = $this->url('home',array(),array('force_canonical' => true));

2.Adding home route in module.config.php

'home' => array(
    'type'    => 'Zend\Mvc\Router\Http\Literal',
    'options' => array(
        'route' => '/',
        'defaults' => array(
            'controller' => 'Application\Controller\Index',
            'action'     => 'index',
        ),
    ),
),

Simple as that.