With the heavier bullets (165 grains and up for the .357, 180 grains and up for the 10 mm) both have plenty of penetration to use for defense against bears.
As I have collected incidents of pistols being used against bears, the primary factors, for a pistol of 9 mm or greater power, seem to be a willingness to shoot, knowing bear anatomy so as to shoot for vital areas, and to keep on shooting.
However, there have been a number of documented one stop shots of Grizzly bears from 9 mm to .44 magnum.
The number of documented bear attacks and defensive uses with pistols are so small as to make caliber comparisons of little value.
My suspicion is that many successful uses of pistols to defend against bears, especially black bears, are never documented, or, if they are documented, are never reported to the public.
No doubt, you’ve researched the matter far more than I. I grew up in Western PA, where we had the occasional nuisance black bear. My dad would always pack his department issued .357 into the woods, and I suppose in my mind that established the baseline for (black) bear medicine.