“It is avodah zara to say that Hashem has any body, or that any body reaches him. This is 13 ikkarim. A rebbe or any other tzadik is not god. He doesn’t have god in him, as Hashem cannot be contained, divided, be here and not there, etc..”
I agree with “a rebbe or any other tzadik is not god”. I can’t be sure that this a unanimous opinion. But as long as it is not associated with any form of actual worship, it is most definitely not avodah zara.