I honestly don't know the details of what happens to the data that is sent in via the toll free number. But since you are the one that has relied on the BBV website, here is what they have to say about the procedures for the Democratic Party caucus:
NO VOTING MACHINES
Democratic Party procedures - Haven't and won't use any voting machines in the caucuses.
PUBLIC COUNTING PROCEDURES
Dem procedures: Stand in a clump, count the warm bodies. Public count. Dem procedures are publicly posted on sec. state web site.
RELEASE OF UNDERLYING PRECINCT DATA WHEN ANNOUNCING WINNER
Dem Party procedures: I have a definite confirm, in writing, from the spokesman for the Iowa Democratic Party that they will release the precinct results. They have never done this before. What they will be doing in 2008 carves out new procedures for improved transparency and citizen oversight.
When people participate in a caucus, they should be able to see the votes counted in public, and then should be able to promptly go visit a web site to see that the result they observed is the same as the precinct number contained in the total.
For the first time, Democratic Party caucus participants will be able to check that the state total uses their accurate precinct details. Maybe -- if enough people ask for it -- Republican Party caucus participants will be able to have the same transparency.
http://www.bbvforums.org/cgi-bin/forums/board-auth.cgi?file=/1954/71028.html