It depends, if you wish to obtain points then spouse has to sit for IELTS. If you will have over 67(surely) then no need. However, recommended to take IELTS,
Since you can get bonus point from spouse i would recommend your spouse to take IELTS ....
For you it should be in minimum band of 6.5 to apply..
for your spouse 5-5.5 will suffice...