Do you get errors or anything?
I use wamp (Windows here) and when it's running any device (tablets,phone,laptops,TV etc.) on the LAN can view sites hosted on my PC by browsing my LAN IP address. You can setup a name to acces the site, for example on my lan "http://localserver/" but lets start off slow.
Without know more about your setup that's all I can say right now.
At the moment (best explanation I can come up with)
I have a virtual host setup as "XXXXXXX:8889/" Which points to the folder where my index.html file is.
When I acess it from my computer which is running MAMP all is fine. When I try from the iPad I get a permissions error and the address displays as "http://www.XXXXXXXXX.com.
So I guess I am wondering how you set up your WAMP to do this and type in your virtual host and be taken to the live web site on your local network.
I al really bad at describing my problem so please be patient.
Viewing on the iPad via localhost would be best done via Shadow if you do not wish to upload to a live server.
Unfortunately the shadow app for the iPad/Pod/Phone that supports localhost connections is still 'stuck' in the Apple apps approval process but it should hopefully be available by the end of this week. Don't forget also to install the latest release of the Shadow build and the app for Chrome otherwise it will not work.
The latest build is version 2 and was released last week - http://labs.adobe.com/technologies/shadow/