Just to clarify:
No kill whatsoever, be it of a GV or a plane, will influence the bomber score(rank) in any way. There is no such thing like K/D or K/S, and there are no kill points.
The confusion mostly comes from two different ways the score can be displayed : On the score page on the website, and in in game by the .score command.
When you have killed another plane, it is not shown on the score info in game (kills will stay 0). But on the webpage score sheet, it will. With killed GV, it's the other way round.
But no matter where and if the kill is being displayed, it's just statistical information only. And as already mentioned, all kills always appear on the pilot stats page.