Raise depth

I will be raising the pool depth in a shot Crete/gunite pool. Going to raise the main drain as required and fill to the level required. We will be drilling maybe two inch holes in the gunite to insert the rebar and using epoxy to give it extra strength and seal the hole. The question is. What’s the best way to mend the old concrete to new gunite? Any special trick to make sure it will not leak water or is just shoot the gunite let it do it’s job and then layer the bond kote thick around the seam? Thanks