score:2
For your answer, we can refer to the guidance, which says...
Source: Visitor Supporting Documents Guide
So yes, your wife's application should include your GWF number in the remarks section, and you should include her GWF number in your remarks section and then explain that you are both applying as a family and that your documents cover both of you.
There is no requirement that the account(s) be jointly held, but it is the normal case when spouses apply together. A note may be appropriate if the account(s) are not joint, but that's your own decision to make.