Diners in Poland has really exclusive terms of application for LOT card, the card is expensive, and - most importantly - not as widely accepted as Visa or MasterCard.
For LOT Senators it is easier to get but still...
I hope another bank will introduce Miles & More card soon, after Pekao SA, Citibank, mBank cooperated with M&M and stopped at some time.
I doubt LH credit cards are available to Polish citizens.