You need to check all the fittings in the spa and pool. Chances are very good that the other fitting will need to be water proofed.

1)chip around the fittings or pipe coming thru the concrete.
2)fill any large voids with hydraulic cement(Water Stop at HD)
3)caulk around were pipe comes thru the concrete, Vulkem 116(or similar)
4)finish by putting another coat of hydraulic cement level with pipe end

When chipping out around the pipes you do not need to remove a lot (1/2")
When you caulk(step 3) make sure concrete and pipe are dry.
Let the caulk sit for a few hours before putting on the hydraulic cement.
You do not need to put more plaster on a patch that will not be seen.