Confirmed, the central report center should be used if it supports multiple content types.
However, wiki entries do currently go to a separate report center. Due to a bug that I'm not sure whether the fix is in Gamma 1 or Gamma 2, many reports would be invisible. Additionally, moderators should receive an alert with a link to it whenever a wiki item is reported, to make up for the reports being separate. I think this is one of the alerts (reports, new posts) that is broken in Gamma 1. A lot of alerts will be fixed by the upgrade to Gamma 2, so you might have a lot of new alerts right after upgrade.