we regularly update our list from Packagist. If you publish your composer package it will eventually show up.
I don't think there's anything else to to at the moment to add an extension to Bazaar. @luceos might know better ?
EDIT: to answer your questions from the other topic, that's right, it's written we do it "without composer". This means you don't need to have composer installed on your server. We are indeed using composer, but that's a local version in the extension that you don't need to worry about.
lol I thought that extension was to sell stuff in your forum ?
Well, it's meant to also sell premium extensions in the future ?