I had that and one that said it granted luck saw no difference in either!

it was my understanding that being granted luck meant that rare collectibles were more likely to show up for a short period of time

When I've gotten "granted luck" I've gotten another event a few minutes later.

Same here. I think that's the meaning.

i thought so too but got nada!

I was just granted vision, went to the graveyard and there was NOTHING.
WHY NOT!!!!!

Recently, I rang the gong and got 'Gong grants Luck' and then I realized that I needed to get the three eligible females to have babies so the tribe would survive. I paired them off, and a few moments later one of my females came out of the hut and she was holding twins! Yay!

WilleWonka~~
You may not have gotten there fast enough.

I too experienced the "gong grants luck" case...and soon after that i had an event...

Yes, the "luck" comes in getting an unscheduled event. The gong doesn't say whether it's good or bad, or even indifferent luck, though; most such events I got were of the "Today is Isola Day" sort, where nothing really happens.