I believe that you also have enable the WOL packet to be forwarded, which is not done by default. So you have to add this statement as well:
ip forward-protocol udp 2304
I believe that WOL uses UDP and the port is 2304. If you have access to a packet sniffer, run it and validate that. In the meantime, if I find out that I am wrong I will post the correct port here.
I would adivse that you add an acl that permits only the souce and dest address that WOL should traverse and which station or stations can generate WOL packets so that you do not open directed-broadcast completely; this is a security precaution to prevent lan broadcast pings and other frames from propogating.
This URL may be of help too:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios122/122cgcr/fipras_r/1rfipadr.htm#wp1018109
Let me know if this of any help.