I have Radmin Viewer 3.5 (portable version) running under Wine on Linux Mint 13 (a Ubuntu derivative) and also on Linux Mint Debian Edition. I am using LogMeIn Hamachi for the VPN and the Haguichi GUI for Hamachi. I connect over the Internet through the VPN. The Radmin Server 3.5 is running on a Windows 7 box, which is also running Hamachi.
Neat trick. It runs flawlessly.
Also read these posts in this forum:
Radmin 3.x and Wine
[GUIDE] How to establish the connection outside of LAN
Google is your friend, but if you get stumped, I'd be willing to answer questions.