I travel all over the Us (Texas, NYC, and Cali mostly) and I've literally never had to put down any kind of deposit or anything of the sort when making dinner reservations, and I frequently make reservations at plenty of nice, upscale places.
Funny enough they also use OpenTable, so no need for this Google stuff — just use the API or book through the site. You can also call them if for some reason that is preferable.