For the record, I have most certainly used analogous innuendo to carefully suggest something about myself to another, when I'm not sure how they'd react, or when I don't wish to be overt about the topic (especially a personal or sexual one).
I don't, personally, think that the wine dialogue was intended to be double layered (I don't believe Larian has the authorial skill to do that deliberately), but I also don't think that reading it as such is unusual - If I were Shadow in that scene, and spoke so, I'd definitely understand and forgive a person who read more into it than I intended to put there, if it wasn't my intention to imply that information.

Everyone here is working with a personal interpretation and reading of the scene - Everyone
Everyone here is working with incomplete information - Everyone

We actually do not know - none of us know - whether that scene was intended to be multi-layed in its meanings or not. We don't have that information, and we may never have that information. the idea that there may have been more to it than the face-value words spoken is entirely reasonable, but it's also not something we can prove or disprove, short of an official comment from her writers.

Everyone needs to acknowledge this and to admit that how they see a scene, and what they feel it shows, or does not show, and especially what they take a character to mean or not mean by the things they say, is Not in any way an objective truth or fact. - Everyone

It's been warned about that trying to tell other people that their opinions about the meaning of a scene are invalid is not acceptable. Treating other posters in condescending or belittling ways when they do not see things your way, or do not agree with you, is also not appropriate; several folks here have been doing that, and I'd like to ask you to please stop... it takes away from the discussion.