For official plugins and theme components (and themes, eventually) you can create a dedicated topic in the proper category with the appropriate tag, or post in the topic itself. Both are fine. 
Though if you post your issue in the plugin/theme component topic you may find it gets to split off into a new topic to keep things organised and findable (it’s great for things like Related Topics, etc too).
I’ve updated a chunk of theme component topics with the info like the official plugin ones already have, but I haven’t done all of them yet - and I’ve also been splitting the existing ones up too. As you can imagine, it’s a bit of a chore so it’s going to take me awhile to work through them all. 