Yes, F1554 grade 36, 55, and 105 anchor rods can all be hot dip galvanized as well as mechanically galvanized.  The only time galvanizing is a risk is when the material is subject to the issue of hydrogen embrittlement, which generally only happens with grade exceeding a tensile strength of 150ksi.  In Section 7 of the F1554 specification under Protective Coatings, it states that hot-dip galvanizing must be done in accordance with ASTM Specification F2329, as well as stating that mechanical galvanizing must be done in accordance with Specification B695, Class 55. It then states in Section 7.1.4 that, “When no preference is specified, the supplier may furnish either..” of these finishes at their discretion so long as the corresponding components (bolts and nuts) are coated by the same process.