works fine for me.
You sure your guild did not leave your current alliance b/c of the new patch? Now, you can join an alliance on any of your cluster servers, so that would be my guess...if not, maybe just logging out and back in should work, but working fine for me here, so I can't think of why it would not work for you, and b/c the patch was partially about cross server alliances, that would be an obvious guess at what problem might be.