Based on survey responses related to this, both of these schools appear in this Princeton Review list:
https://www.princetonreview.com/college-rankings?rankings=great-classroom-experience
For an opinion on Williams in the context of comments on other liberal arts colleges, see reply #7: Struggling with D21's List. ED & ED2: Amherst, Hamilton, Wellesley, Vassar.
Regarding U.S. News rankings, note that, by overall score, Bowdoin (91) places equidistant between Williams (100) and Bates (82).
There may be a tendency on CC to characterize schools as peer institutions (or not) without objective support. Without expressing an opinion on these particular colleges, I think your inquiry here represents a valid one.