i ran into this a while back. d1.4 is a book for supporting steel. It is perfectly understandable for very serious applications, such as long span bridges or high rise structures. However, in the situation I ran into, rebar could either be tied or welded, but, if it was welded the welders had to run qualificatin test and procedures qualifications. Of course this is very costly, especially when the rebar can just be twist tied with those silly little wires.
If the engineer, inspector, or owner is not pushing the issue, don't bring it up. It would be a good idea to follow it, but, don't get yourself into a situation that somebody says "hey, maybe your guys should qualify to the D1.4". If you do, you will regret it.
Oh, and the filler will probably a 90 KSI or higher.
Good Luck!!