They will extend their feeding tentacles at night, after you turn the lights off. They will eat meaty foods, not so much phyto, but stuff like krill, brine or mysis. I have three different colonies of candy canes in my tank, one that has 20+ heads of pink, one that has 1 head of blue, and another that has 30+ heads of brown/green. I never used to feed them, but once I started, they began to bud off a new head every other week or so. I now hand feed them after I turn the lights off every other day or so. I think that if you do this, you will see sooo much more growth from the candy canes. For example, I had the one solitary blue head for at least 6 months, and it never grew, never split. I started feeding it every other night, and within a few weeks it had started to split.
You also don't need to feed your zoas phyto. They will get enough nutrition from the lighting and I think that if you are adding phyto for your tank and all you have are zoanthids and candy canes, you are just adding nutrients (nitrates, phosphates) to your water and can end up with algae problems.