When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
What you see there is that the JCR rack has welded mounting plates where the brackets mount with two bolts each. The bracket clamps to the gutter, but it doesn't clamp to the rack, so it isn't "one size fits all."
Whether it will work with the Yakima rack will depend on whether it's wide enough to meet the brackets where they stick up and whether the rack itself has mounting points. I'll go out on a limb here and said that it's probably not going to work without some extra fab on your part to adapt the pieces to fit.