+1(514) 937-9445 or Toll-free (Canada & US) +1 (888) 947-9445
Yes, since you guys are family
 
My wife and I are applying for Citizenship. Can I post both applications in the same envelope?
YES.

from CIC website

"Family applications: If more than one member of your family is applying for Canadian citizenship, send all of the applications together in the one envelope. The applications will be processed together. We will try to schedule family members together, but sometimes, it may not be possible"