Is there a reason you are keeping them entire? This is a common problem with entire males, or if you have one entire and one desexed.
You male Collie is also going through adolescence which is a difficult time even without hormones to contend with. I would definately consider desexing one or both of your dogs.
With the Collie try the Nothing in Life is Free (NILIF) program, this will add routine, structure, guidance, and leadership, which is great for adolescent dogs. You can do a search on the forum or the internet for more info about NILIF. Here is an excerpt from Dr Ian Dunbar about the program.
NILIF operates on the basic principle that before a dog is granted anything that he wants in life - treats, petting, to go outside, to come inside, etc. - he must first do something for his human, like perform a sit/stay...Dogs do what works. If a particular behavior in a particular situation tends to result in Good Things For Dogs, then the dog will probably stick to that behavior. If it doesn’t, the dog will probably abandon the behavior. Set up your dog’s life so that good behavior consistently pays off for the dog and bad behavior does not, and you should have a delightfully obedient and well-mannered pet. Your dog learns that the best way to get what he wants is to look at you and offer the canine version of saying please. It’s a simple principle, but not necessarily an easy one to implement. One word in my little aphorism accounts for a lot of the difficulties people have in training: consistency.
I am not a fan of allowing dogs to duke it out for alpha positions. If you do not like a behaviour then it should be stopped. You, after all, are the leader and they need to behave according to your rules.
I would also seperate your two dogs. Only leave them together under supervision and make sure your Collie is calm when he is around your Sheltie. For example, you can try teaching them both 'on your mat (or bed)' and get them to lay down initially when they are in the room together so they start from a calmer position. But keep their mats at other ends of the room so they cannot eyeball each other. While this is going on I would not even think of letting them close to each other, they are not going to play so its really not worth encouraging the behaviour by giving it the opportunity to occur. I would also feed them seperately and not have any high value resources around for them to fight over - food, treats, toys for example. I would not bother trying to treat them for being calm around each other as I think introducing treats into the mix will just make matters worse.
Your Collie will probably pass through adolescence around 18mths to 2 yrs and things may calm down then. They may never like each other, what you are aiming for at this stage is to get them to tolerate each other. Adolescence is trying for dogs and owners so good luck.