Design Strength Factor for Stand-Off Anchor Bending

For stand-off anchor bending, I know this method is based on ETAG 001 Annex C. For the final design strength, why does the method used by Hilti use a phi-factor from ACI 318 rather than the partial safety factor used in ETAG 001?

For example, ACI would use a phi-factor of 0.75 or 0.70 depending on whether supplementary reinforcement is present or not. But, ETAG 001 Annex C uses a factor of ultimate strength/yield strength. For an ASTM F593 threaded rod this could have a partial safety factor of 100,000/65,000=1.53 or 85,000/45,000=1.89, with an equivalent strength reduction factor of 1/1.53=0.65 or 1/1.89=0.53.

It just seems to me that if we're adopting a method from a code besides ACI 318 that the same strength reduction factors would be adopted as well.