Is Vela Air approved by the CAA or EASA?

No. Vela Air is a supplementary planning and situational awareness tool, not certified avionics, and it is not approved by the UK CAA or EASA as a primary source of navigation or aeronautical information. Always check official sources, such as the UK AIP, NOTAMs and an official weather briefing, before you fly. The pilot in command is always responsible for the flight.