Originally Posted by cdodkin
works both ways for me
Have you checked your settings in iTunes when the iPhone is plugged in?
Dock your iPhone, select it in iTunes, then under the INFO tab - you should select Sync iCal Calendars, then select 'selected calendars', then check all the calendars on your Mac that you'd like to sync to your iPhone.
Then select APPLY or SYNC at the bottom of that screen.
Thanks. It turns out I needed to clear my iSync history on the Mac. Now it works great.