But I haven't found specific info which is what I need for my business plan.
In general, in Poland:
If you're running a good bar, count on a minimum of 12-15zł an hour in hand (add another 30% for gross labour costs) for an experienced person who knows the topic (in your case, craft beer). The manager should be salaried, and you'll need to pay them at least 3000zł in hand, but look at 4000zł to get the right person.
But the market is saturated in Poland already.