The documentation for submitting plugins says I have to have my plugin published to JCenter/Bintray.
I was wondering if I already have my plugin published to Maven Central, is there a way to publish it on plugins.gradle.org without having to go through the Bintray process as well?
Unfortunately, no, not that I’m aware of. The Gradle Plugin Portal is integrated only with Bintray. Additionally, it requires some additionally metadata to associate a particular plugin id with an actual package which is only available in Bintray.
If you want to avoid having redundant publishing logic in your build, you can configure Bintray to publish to Maven Central for you. That way you can simply publish your plugin to Bintray, and then Bintray will handle publishing it to Maven Central.