The shallower seat tube angle of bike 2 (M/L) increases the effective top tube length of that bike.
If you are currently running a setback seatpost with bike 1 (S) you may want to use a straight post with bike 2 since the shallower seat angle will place you farther forward in relationship to the bottom bracket/pedals.
Note that the stack on bike 2 is 14.4mm higher than bike 1 so your bars will be considerably higher unless you are currently using a stack of shims under your stem.
Brent