The various tabs on the per-site Top Questions homepage have, at the bottom of the right nav, an RSS link for the selected tab. However, these are currently not correct for the active tab, for most of the tabs.
For tab... the RSS link is ...
Bugs Monthly questions feed
Reqs not present (but that's probably correct)
Active Recent questions feed (probably by design, but not actually "active" questions)
Bountied Bountied questions feed (correct)
Hot Bountied questions feed
Week Hot questions feed
Month Weekly questions feed
Other sites don't have all those tabs, but the ones which are present are incorrect in the same way.