I guess you could just be totally open about it, and change the wording to something like "the open-resume design already helped some people land positions at",

I guess you could just be totally open about it, and change the wording to something like "the open-resume design already helped some people land positions at", then show the logos. That way you are being honest, and doesn't look like a direct endorsement from those companies. You get your logos for "marketing", and you are safe from misinterpretation. IANAL.