Or is this only for discussion and not, e.g., bug reporting?
If you see the FAQ's on Area 51 it says the following:
What kind of questions can I ask here?
The Area 51 Discussion Zone is for users of Area 51 to discuss new proposal ideas, existing proposals, and anything else having to do with the new site creation process on Area 51. For example,
- Should we merge the _____ and _____ proposals?
- Do we really need another site about _____?
- Would a site about _____ work in the Stack Exchange network?
- What category does the _____ proposal belong in?
What kind of questions should I not ask here?
You should only ask questions about proposals. You should not ask questions about the site itself, like bugs, feature requests, or support issues. Those meta questions should be asked on our meta-discussion site.
So to report bugs on Area 51 you have to report them over here.
Hope that helps.