Good night, I couldn't find any place talking about it, but I really wanted to take this doubt away.
I like to do Shiny Hunt and usually use buffs (Shiny + Week)
I know that the probability of showing a shiny is 1/4096 without buff and 1/3266 with buff.
But my question is ... How does it work if I'm at a party?
Example 1: I using Buff and the other person without Buff?
Example 2: Both using Buff?
If you search in party then everyone has his own spawn. So when you go into battle one of the 2 or 3 pokemon has an increased chance of being shiny. if you all have the buff on then this applies to all spawns.