The marrow you're getting out of a marrow bone (ie: the marrow you're getting when you order a dish at a restaurant that has "bone marrow" in it, or features marrow) is also not the same kind of marrow as is in the thin/small bones you're getting in a steak. No, I don't think marrow is making bone-in steak taste better.
(Marrow, though, would make a steak taste better! Order a marrow bone, cook the marrow, and then baste your steak with it when you sear it.)
(Marrow, though, would make a steak taste better! Order a marrow bone, cook the marrow, and then baste your steak with it when you sear it.)