I couldn't quite work out when they were neutered but if it was over 6-8 weeks ago then I would start bonding them, it'll only frustrate them being next to each other with no physical contact.
Same as any other bond small neutral area, supervised, no toys or litter trays just loose hay.
With boys I often find that you need to increase space more gradually than with mixed sex bonds.
Personally I find boys easy, its always the girls that cause me trouble. :lol: