Vega 20 seems to also refer to a discrete GPU. This has been later rebranded to Radeon VII (maybe because of this confusion). The number you are quoting is for the discrete GPU.
Same with 10 LOL. VEGA10 codename is for the original Vega Frontier Edition/RX Vega 56/RX Vega 64. But now there's also "Vega 10" used as a description for the 10 Vega compute units on Ryzen APUs.
I was talking about the mobile GPU on MacBook Pros which is based on a 14nm chip. The full name is Radeon Pro Vega 20:
https://www.amd.com/en/graphics/radeon-pro-vega-20-pro-vega-...
https://www.techpowerup.com/gpu-specs/radeon-pro-vega-20.c32...
Vega 20 seems to also refer to a discrete GPU. This has been later rebranded to Radeon VII (maybe because of this confusion). The number you are quoting is for the discrete GPU.