I don't have enough "data" to add this to the Wiki, but if you want the points (in addition to the convenience of making the reservation), be sure to make the reservation directly with OpenTable (web site or app), NOT through the OpenTable reservation link on a restaurant's web site.

That is, I have had several experiences where I have made a reservation through the OpenTable link on a restaurant's web site, and found a note in the confirmation that I would NOT be receiving any points for the reservation. I then cancelled that no-points reservation, closed my browser, re-opened the browser, and went directly to OpenTable to make the reservation ... and the confirmation stated I would get points.

I say "close the browser" because the first time I tried re-booking directly through the OpenTable web site, it seemed to know/remember (cookies?) that I had previously made (or tried to make) a reservation through the restaurant's web site, and again the confirmation said "no points". YMMV.

P.S. to crabbing: Thanks, for starting the Wiki.