My understanding is everyone gets 8 from the daily Check-In, with the Jackpot being the variable part based on clan size and activity. The Jackpot currently seems highly unreliable, some days we receive it, others we don't.
As for the jackpot rewards, sometimes when you open up the Clan menu it briefly flashes up the jackpot reward, but fades before I've been able to take a screenshot. It looked like it wasn't just Tributes but could also give both types of Sand. I didn't received anything that day though.