Michael liked Liz a lot better now than he had when she first popped back up in their lives. To be fair, it wasn't really ever her that he disliked, it was the way his brother acted when it came to her. Which wasn't exactly Liz's fault. He actually enjoyed working with her on the cure for Isobel and wasn't opposed to having her run some tests to learn more about their alien physiology.
Still, he wasn't the most demonstrative person, emotionally or physically, so he gave her a mild greeting when she joined him at the table.