With the ribbon: people in the US used to wear different color ribbons to show they supported different serious causes -- red for AIDS awareness, for instance. I think the joke is that Phoebe just made up a cause (Christmas!), and her cause was completely ridiculous and apolitical. Ribbon wearers were usually very serious and earnest (about their cause at least). People may still occasionally wear ribbons, but it was a fad awhile back. I don't remember the scene with Ross, but I suspect in this case "Two down" means that he has completed two tasks, and now has 12 minutes to complete any further tasks. He implies that he thought that he would not have so much time left. Hope that helps! :-)

Phoebe is just being sort of dumb. Christmas is not a political holiday and that's sort of the joke. Two down... Say you have five things you need to do before you can leave work. You accomplish two of them. You can say "two down and three to go." In the show he didn't finish the phrase but presumably he has a certain number of things (or people to get ready?) before he can leave and two of them are done.

i don't know

Here is how I see it as a native speaker. Someone please correct me if I'm wrong! 1. Phoebe is supposed to be kind of dumb, so some things she says might not make complete sense. The bow probably doesn't actually mean anything political. Maybe she is thinking of the way someone might wear a ribbon supporting breast cancer awareness or something like that. So it is just a joke. 2. I haven't seen that episode of Friends in particular so I don't know what he's talking about, but "Two down, one to go!" is a pretty common expression. It means you have completed two out of three things you had to do, and there is one left. He just left off the "one to go" part in this case, I guess it is implied. For example, if you had to clean three rooms, and you had finished with two of them already, you might say "Well, two down, one to go!" It usually means you are almost done with the entire thing. Also it doesn't have to be 2/3. You could say "Five down, two to go." It just signifies that you are nearing the end of the task usually. You can also use it in a joking way if you said something like "Ugh, two down, a million to go!" Just to exaggerate, if you were just starting with something. Hope this helped! Cheers!