Don't think there's any bias or conspiracy, just a poor level of officiating in the game. Like referees don't have a conspiracy against Wolves either. The refs are human, and mistakes are fine. Seems we've been on the bad end of some really contentious calls this season though, but it will even out I am sure.
However, I would have given both of those pens in real time last night. The frustration comes with the added layer of VAR looking at both, and you're watching and thinking "hmm, that doesn't look like a pen". Like what's the barrier for 'clear and obvious'? I remember the one that was overturned in our favour against Arsenal. There didn't look to be much difference in that decision vs both those pens last night?
There's definitely more of a reaction for calls in our favour though. Like, you'd notice even from a subtle perspective, in the post match on BBC the other managers comments will be there if there's a contentious call, whereas often times this season EtH's complaints won't be referenced. However, I also think he doesn't complain enough, so that's a contributing factor. I really don't think much of that is actively in the refs head in the heat of the moment either way. Unconscious bias, at the very most I'd say.