I have an Android device as well... I sync my Feng Calendar to Gmail, like you would any other remote calendar in Gmail.
Perhaps this is an obvious suggestion, but you have to manually add the calendar on the device itself.
I did notice that the ical in google doesn't always update, if I change the Feng Calendar - my goog calendar doesnt always reflect those changes though... but that was in 1.6.2, so I'd have to test that again in 1.73