People put way too much emphasis on that dialogue at the Church (obviously the priests and religious fanatics would be wary of the presence of Ren'dorei). Aside from that, you see Ren'dorei chatting and walking with every other allied race, Umbric has developed a friendship with Wyrmbane and Shandris, and Alleria obviously is respected as a leader equal to all the other allied members, and has developed a close alliance with Mekkatorque (as can be seen at the Battle of Lordaeron). The Ren'dorei have fit very well in the Alliance, in spite of their condition.
They are not the "Forsaken of the Alliance", basically. They are in good terms with pretty much every other Alliance race. Even the Lightforged! As I was saying, in Stormwind you have Ren'dorei and Lightforged chatting and walking together.
That's also why I am scared of Alleria and Turalyon working together, hopefully nothing happens in the novel that causes a fallout between these two races.