It depends if the bike lane is drawn as its own way or not. Because it is included as a tag, it makes sense to center the line in the middle of the entire span. I think it makes more sense as to why when you look at it with the JOSM lanes plugin. Centering the way in the middle of the drivable space means that the way's width will be too far to the west and not far enough to the east, in this case. Centering it in the middle of the driving lane also implies that roads are for cars — and while that might be the de facto norm in North America, it isn't strictly true.

But I haven't been able to find any discussion on it. I've been following the way that it was done in other areas I used to map, and whenever I've encountered a road here that was not aligned to the middle of the physical pavement it seemed to be because there was once a bike lane mapped as a separate way that was removed. (Usually you can tell because of some leftover nodes.) So I moved them back into alignment as part of the final cleanup when adding the bike lane tags.