Can you physically see spirit companions in the physical world or only in the astral?
Depends on your skill level!
I was born with the ability to see spirits in the physical as though they were a cat or dog. I quickly lost that talent, but I believe it’s possible for anyone to gain the skill. While it may take years to be able to sense spirits in the physical, (not see per se, just kinda….know where they are and what they look like) it may take decades or longer to be able to fully see spirits in the physical. Sometimes I get glimpses, and I know spirit workers who have been doing it for decades sometimes see glimpses.
So, yes you can. You can build up to that skill. It’s just going to take many many years of practice and sense building.