I think this depends too much on your network layout for anyone to be able to give very much help. It also depends a lot on which method you use to access the SVN repository: http/https, svnserve or svn+ssh.
What you need to check is that the Wi-Fi connection is in the same "network" as your LAN cable. You should also check if there is any filtering between the Wi-Fi and the LAN. The person who configured your network should be able to answer these questions.
Kind regards,
Daniel