Was this a "field bend"? If so, did they use a torch to heat up the rebar before bending? This could cause the bend area to become very brittle after cooling.
You are correct that many "hybrid" adhesives such as Epcon A7, Simpson AT, Hilti HY 150, etc. do not perform well in underwater conditions. This is due to a couple of issues, these type of adhesives generally do not bond well to smooth core drilled holes and also are specifically not recomended...
ACI 318-05 addresses this question in section D.5.3 for a J-bolt. The pullout strength of a single anchor is in section D.5.3.1 with the formula for a j-bolt in section D.5.3.5. You will see that the pullout strength for a J-bolt is much less than a headed bolt (D.5.3.4)