No, the media anthrax was also analyzed at AFIP, just as Ross says. In their Newsletter they only talked about the silica they found in the Daschle sample. However, they also found silica in the media sample. Much more silica, in fact.
Did I say otherwise?
When Tom Geisbert visited AFIP on October 25, 2001, he took along ONLY a sample of the Daschle anthrax. If and when AFIP tested a media sample, it would have been later. Since there's no information about it, it could have been a day later or even a couple months later.
Presumably, however, they didn't SEE any "silica" in the media anthrax, either. They just DETECTED silicon and oxygen via their EDX.
If there was silicon and oxygen in the "crude powder" sent to the media, that almost certainly indicates that the silicon and oxygen came from some part of the fermenting process. It means it had NOTHING to do with weaponization.