the limitations to that seatpost clamp are the fingers of the aluminum top half of the clamp... being Cast aluminum, they WILL BEND, if over-torqued... and once cast aluminum bends, it is going to break, eventually.

Standard "torque specs for steel bolts" are going to be too much for that aluminum clamp... they refer to the steel bolt screwed into a steel part.

good luck.
i'd think a bit less than half the steel/steel torque might be a good starting point... or less. the length of the clamp fingers will play into it, and keeping seat in position is the only goal, not achieving some torque number.
start light, and work up to the goal.