Mint is not a good companion plant for much of anything. It rapidly takes over whatever pot it is in and crowds everything else out. If there is any repellent effect of the chives and garlic, it will work just about as well if the pots are just next to each other. For more effectiveness, puree some in some water. Let it sit and infuse awhile, then strain the solids out and spray on your mint.
For spider mite control, spray the plant with a soapy water solution (soap, not detergent which can burn your plants, dish "soap" is detergent). Water the leaves frequently and keep the plant well watered.