Had 12 PE legs in the last 18 months of so, mostly BA. Normally get offered 2 drinks (i.e. wine plus another wine, or g&t plus a wine for dinner). Just ask for more if needed and they've never batted an eyelid.
On AA PE they served one drink then bottle poured wine for the meal and the same on CX PE. Had to ask for more wine when wanted as they were not serving it in the little bottles. Must admit that CX were terrible at filling the glass. Barely half full in some cases.