Tried using Alliance against a number of targets ranging from green to red when servers came back up today. Every time, I got only an error message: Your spell did not take hold. The brownies I mentioned earlier, however, would not be a problem regardless of alliance working or not if treeform modified my faction with them properly; a poster here mentions that it raised him from dubious to amiable:
http://web.archive.org/web/200010201...lID=171&Page=2