My vet reccomended keeping them seperate for 10 days, so I seperated them but kept them together with wire between them. I also supervised them being actually together so that the bond wasn't broken, I would have probably put them together straight away but Leuki, female who was spayed kept stamping her feet and running away from Samba, which is VERY unlike her. So I just presumed she wasn't ready and waited till just over 2 weeks when she stopped doing that. It was then very easy to get them back together.
Because Leuki was 1 when she was spayed they did used to chase each other occasionaly and hump each other (dominance other one neutured - although they were also the best of friends) before the spay. I just didn't want to take that risk with that happening.
Basically I would say make sure they can at least always sniff each other, and I placed their beds next to each other as well, so they were forced to sleep together (through wire - I don't know the technical term sorry!)