@wavernepal: Haven't heard that and not sure whether it is recommended or not. In any case, if you do send together, put a printed sheet at the very beginning clearly saying this package contains TWO applications, and list the names. After that, 2nd page maybe you should insert a page that says something like "Applicant: [Your name]". After your application, put another printed sheet saying "Applicant: [Your wife's name]". Maybe good to use paper clips to separate out the two applications as well.

Not professional advice so you may want to consult a professional. GL.