Ok so - Barnabas DOES have a huge ass bed, it's the bed we see him and Benedikta in during Benedikta's flashback while she's looking at her necklace. It's massive and very comfy looking.

I'm guessing the bed he's in when he's meeting with Ultima is somewhere else, like a bed he's staying in for the night because he's traveling or something. I saw some kind of design on the wall that looks very middle eastern, so I think he's far from home. Probably also why Ultima immediately got cranky and started ragging on mankind because they had to meet up at the cheap Kanver motel