Can i use 1 ground wire to ground 2 outlets?
If the water pipe is used as a grounding electrode for the electric service, AND the point to which you're attaching the ground wire is electrically continuous back to where the grounding electrode conductor attaches to the pipe, AND the grounding electrode conductor between the pipe and the service is properly sized.  

Then yes, you can attach a properly sized grounding conductor to the water pipe. That grounding conductor can then be used as the grounding conductor for multiple outlets.   

This is exactly what Harper said in their answer, on your other question. See NEC 250.130(C)(1).