Do you think Adrien thinks he's friends with Alya?
Perhaps not as close as Nino, but I would definitely say he’d think himself friends with Alya. She’s very confident and outgoing, and when he thought it was only her on the train, he had no problem waving to her.
And when he thought the designs were Alya’s, he had no problem going up to her and starting a conversation about it.
I honestly think he thinks he’s at least some level of friends with Alya. It’s enough where I can even see the Alyadrien ship happening if done right.