Candy from feeding

It'll drop just like a buddy candy-- top right, just above the +20 stardust you'll get from that same berry.

I've noticed 15 or so candy since remote feeding became possible, I never noticed anything before remoting. I'm done berry feeding though. Gym control bonus is more meaningless than 20 stardust---fed 2000 berries. Most received Porygon, Snorlax, Chansey, a couple Dragonite, few other worthless ones

I only noticed one Snorlax candy out of 600 berries. Could be that I didn't pay enough attention, but they seem very rare.

During the double everything event I thought I noticed a +2 twice in a row feeding Blissey - and although not 100% positive I think the Chansey candy count did actually go up by 4! That's the only time I've noticed, but I'll take it! I have less then 100 feedings to go for my Gold badge.

My guess is its about a 1/50 from my experience . I always look at the corner when feeding and quite often see a candy pop up

It's hard to notice unless you watch the top right corner for it. I'd say that 1/50 number is close. I only feed berries remotely so I don't power up someone else's mon. After I load up my bag in the morning between 30-50 berries I usually get 1-2 candies out of it, as with RNG sometimes it's zero and a few times it's been 4. Right now it's my main source of smite and Ttar candy.