The amount of VRAM on the GPU has no bearing on how the CPU performs, as the VRAM is independent and only accessible to the GPU.
That being said, the RX 470 would probably become a bottleneck to the i7, long before the i7 became an issue. That i7 wouldn't even bottleneck a Vega GPU or 1080ti/Titan XP. It's actually rather imbalanced of a match up.
An Intel i5 or Ryzen 5 CPU would be more balanced, but if you plan on buying a higher end GPU in the future, then go for the i7.