I have observed the same problem. The ranking window no longer has the torunament tab, instead it has a fellowship adventure tab. I've tried this with both MS internet explorer and firefox. I've exited the browsers, cleared cache and even rebooted the computer to no avail. The tournament tab was there an hour of so before the tournament ended today. Now it is gone. I checked with a couple of people in my FS and two out of three are having the same problem. One now has 4 tabs, the usual 3 plus the one for the Fellowship Adventure.
Also, myself and the two having the problem have another one, which may be related (or not). The tournament tab on the FS window does not load the list. It shows "Loading data. Please wait...". So I wait and wait. I came here to see if others have the same problem. I bet it'll be waiting when I get back.
At least I still have chat. (tempting fate with that comment.)