Specifications call for 2 inches of concrete cover over reinforcing steel, and this seems like something that should be particularly observed to avoid either staining or spalling of architectural concrete. But what happens where the tie wire on the rebars comes closer to the surface than the rebars themselves?
All ties should be bent away from the forms. All tie wire clippings should be swept away and not allowed to remain on horizontal surfaces such as soffits where they might become exposed to weather or to view. This is particularly true if the concrete is to be sandblasted. Soft stainless steel wire is the best kind to use for tying reinforcement in architectural work.