VIPs are not exposed in the API
https://twitch.uservoice.com/forums/310213-developers/suggestions/37563241-expose-vips-in-the-api
You would have to have a Twitch Chat bot that connects to chat and runs /vips and parses the response to obtain the current VIPs and from there you have your list.
However, a discord bot cannot easily get a Discord’s users TwitchID’s so you’d have to devise a way to link Discord and Twitch accounts together as well