I don't really know what to expect from Bina's passive at this point. I remember when 6.0 datamines first started coming in and we learned of Moonsign people thought she'd give a +2 boost to your moonsign level but this was due to dataminers being retards and misunderstanding of the tooltips and thinking level 0 (not having any NK characters at all) was a third level meaning it scaled with 1 to 3 characters
If we suppose Bina does give a +2 bonus this does absolutely nothing for all of the NK characters since you'd need to put both Columbina and whatever Nod-Krai character you want in a party together anyway, which would naturally bring your level to 2. The only instances where it'd matter is if you wanted to run Columbina without any other Nod-Krai characters in the party (assuming she has enhanced talents and effects at Ascendant Gleam) but then you wouldn't have any of the limited electro dendro characters to enable you to trigger lunar-charged or lunar bloom. Alternatively the only other option is that it'd be a global passive which they obviously won't do either
Therefore I firmly do not believe that Columbina will have a passive that increases the Moonsign level past the usual 1