As far as I know, Hybrid SLI only works when combining a dedicated Nvidia graphics card with an on-board Nvidia chip on the motherboard. Also, I know it works for Windows, but I'm not sure about Linux. Make sure you check that first.
"Hybrid SLI® technology, based on NVIDIA’s industry-leading SLI technology, delivers multi-GPU (graphics processing unit) benefits when an NVIDIA® motherboard GPU is combined with an NVIDIA discrete GPU. Hybrid SLI increases graphics performance with GeForce® Boost and provides intelligent power management with HybridPower™. "