Graphically speaking there's not that much difference between a 1050 4Gb and a 1050ti 4Gb, maybe 5-10fps at identical settings. But thats not including power consumption when relying on a battery. The 1050 has a lower power draw overall generally, so would be better on battery life. But that isn't comparing actual batteries, if the $960 laptop has a considerably longer lasting capable battery than the $720 laptop, even power differences will be in the more expensive laptops favor.
Don't base your purchase from the gpu alone, you'll have to look at the big picture and decide exactly what's going to be more useful. And then decide if the $240 difference is worth the price.