"Increases the likelihood of obtaining larger bounties/excavating more provisions" seems to indicate you would garner the same items you would have gotten without Yeestog for each attempt, except a chance at more of each. E.g., maybe for one attempt without Yeestog, you get one platinum ore. With Yeestog, you get a chance at more than one.
"Occasionally grants additional gathering opportunities/mining opportunities" seems to yield the same number of items you would have gotten without Yeestog for each attempt, except you get more attempts, so you'll get more chance at different items.
Neither option automatically yields anything different per attempt, just increases your chance of it happening. So, setting Yeestog to larger bounties won't automatically yield more for each attempt than you would have gotten without him, but makes it much more likely.
If you want more variety of items, you should go with additional gathering/mining opportunities. If you want more of each item, go with the other option.--Snorglepuss (talk) 21:25, March 19, 2020 (UTC)