Both ST holders and members accumulate loyalty points for attending matches (both home and away), but ST holders always take priority over members for away tickets and neutral venue tickets like cup finals. Loyalty points only count for the last 4 complete seasons and the current one.
For this semi, all of the ~20k ST holders were given about a week in which they could buy a ticket, and after that the remaining tickets in our allocation were allocated to members who applied, based on the members' loyalty point totals.
There could conceivably be situations, e.g. a Europa League final, where our allocation could be less than the number of ST holders, in which case ST holders would be allocated tickets based on their loyalty point totals.