The redirecting works with Flash clients that support the NetConnection redirect call.
When using the Loadbalancer addon for HTTP based streaming clients, you will need to use a 2 step approach. First you will need to send a request to the loadbalancer service which will reply with the IP of the least loaded server.
You will need to use this URL to get the least loaded Wowza server:
You can use the IP from the response during the second step when you construct the streaming playback URL, which will be passed to the media player.