Same problem in CS6: neither "Fit to artwork bounds" nor "Fit to selected art" will record for me (although strangely, "Fit to selected art" recorded on the first attempt but never worked again, even after restarting).
Seems to be one of these temperamental flakey things that sometimes conks out. I imagine trashing preferences would fix it, but it's not worth it since the workaround works (albeit clunkily):
- Flyout menu in the the Actions palette
- "Insert menu item"
- From the top menu, choose Objects > Artboads > Fit to Artwork Bounds
Even this seems to be a bit temperamental, though. Sometimes it seems to not actually size the artboard down properly, and sometimes it seems to give different results for running the same action on the same file. Something that seems to work more reliably is the following in your action:
- Fit to Artwork Bounds
- Select all
- Fit to selected artwork
In theory that's just duplication, but it seems to work more reliably than just one or the other .