Seems http://ftp.netrek.org doesn't have the latest Vanilla release.
Looks like only the SourceForge site is being updated with releases
for the past 3 years. Here is the latest one that's up there:

/pub/netrek/servers/vanilla/Vanilla-2.9pl8.tar.gz          
05-Dec-2002 21:32   952k

If you stick the latest release, Vanilla-2.10.2, up on ftp.netrek.org
perhaps you can update the Vanilla page to show a link to it (it
already lists several methods for getting the client):
http://vanilla.netrek.org/

Zach