If you feel that he's creating an atmosphere that makes it difficult for you to join in, then I would ''shine a light on it'' as they say.
You: Bernard I feel like you're creating a bit of an atmosphere. Is that your intention?''
Chances are he's going to say ''no, no, not my intention!'' and if he does say that you must take him at his word and say ''Im so glad''.
It sounds like a nothing exchange but it puts a potential bully on notice that you might not be as easy to push around and manipulate as they had thought.
If he says something like ''yeh, I can't be arsed saying good morning and good afternoon and you're far too cheerful for the morning''
You could say, ''that's been noted Bernard, I'll meet you half way. I won't single you out for any pleasantries if you could attempt to disguise how you feel about me.''
If he says something churlish like 'do what you like''
Just say ''glad I can count on you to juuuust be professional and civil'
I had an experience at work. A woman cast me in the role of her enemy and I let it slide for months and months until I realised she was love bombing all around us and treating me like a ghost and I was given a strange look if I tried to join in the conversations.
She'd made it a thing that I wasn't included. If I spoke at all she'd say ''oh, could you hear?'' in a shocked voice. Or she'd react to everything I said like it was too risky or inappropriate or too boring or not interesting enough or that I didn't know and hadn't fact checked.
She certainly didn't hold anybody else's contribution to the conversation to such a high account, and all she ever did was simper.
A vacuous article who needed a lot of validation, and yet she did successfully exclude me. So be careful and nip it in the bud.