The only way you can get assigned a siba trip is to be awarded the current siba bid. The folks in the building, plus the bidding software(which says you are bidding xx of xx siba, instead of the normal number), won't give it to you. The instructors are pushing this too, as they won't let someone come by on a day off and take the siba course and sim to get the qual....it is all by award.
The vto assignment is the fix to the seniority issue where the siba FO's were getting the cherry trips out of seniority order. The first fix, put the siba vto's at the end, so when the trips ran out, they got R days, and the junior domestic guys were getting better vto's. Hopefully it will work out as it is intended to.
HJB