i think waiting a few days is a good idea
however- i would make sure to keep at it relentlessly. i think taking too much time off may allow them to think its finally over and they dont have to hang out anymore.
so i think a just a few days like you said is the best route b/c that gives Alex time to forget about the fight a little, and it also give Ryo time to calm down.
i know how it is whith the over-territorial female bunny. and i know i've said this before, but my older female is also the fight-starter with my two. however- in time i think Ryo will realize that she can share her love with you and Alex, and still recieve the same attention fomr you, meanwhile gaining a new buddy!
i say, just no matter what- don't give up! i think i gave up on my two way too soon and now its been a year and i would just never trust them together even if they ever got along! so i think the more time Ryo and Alex can spend together the better things will go.
oh- and also- i dont think you need to start the whole bonding process all over, but i would keep them in the neutral area teh next few times and make sure you stay with them until they start to relax with each other again.
how is Alex's bite? these litte bunnies seem to be pretty uneffected when it comes to bites, or is that just mine? i notice when my rabbit Sniffles got bit in the past she was up and running again in a few minutes. hehe/ maybe shes just a little brute, i dont know! haha