Applying to a Math PhD program which doesn't require GRE as a physics/math major I finished BS degrees in math and physics, and doing MS in physics.

I will be applying for PhD programs (mostly physics), interest in mathematical physics, and have taken only the Physics GRE. I found that Stony Brook mathematics dept does not require math GRE, so I am asking:

Can one expect to reasonably predict if it look bad to apply without a math GRE score, given that my background in math is (all pure courses starting from multi-var calc/linear alg/diffeq two semesters of analysis one semester of abstract algebra, undergrad diff geom., two semesters grad. diff. geom., currently in grad. analysis (and of course self-taught measure theory and point-set topology, complex analysis)) all A's.

No publications so far, but independent study in physics in understanding solitons of various classical field  theories, and string theory interpretations (used a little diff. geo (ADHM)).

And could one be able to predict if recommendation letters from at least one string theorist in a physics department will have as much impact as a rec. from a mathematics faculty?

Thanks
I don't think it will prevent you getting accepted.  I followed a similar path (Physics + Math BS, Physics GRE only -> Applied math PhD).

But I recommend that you decide who you would like to work with in the places you'll apply to, and write them a very polite, short e-mail explaining your qualifications and interest.  If a faculty member is interested in you, GREs won't matter at all.