[App_rpt-users] RF Linked Radio to Allstar for Voting

We have finally located a site for a remote receiver that we want voted using Allstar. But it has to come to us over 900MHz first. I realize that I can put a RTCM on the receiving 900 at the transmitter end but will it vote? As it is I have never done a RF link and I am concerned with sending 4.2KHz audio (our area uses 4.2KHz max. deviation) over 900 that uses 2.5KHz audio. Do I pump it back up to 4.2KHz in the RTCM? Thanks.