Antonyms for "more bantering" would include serious, earnest, somber, grave, solemn, and sedate. Bantering is a lighthearted and playful form of conversation, and the opposite of this type of communication would be one that is more formal and serious. For example, a serious conversation might involve discussing important topics such as politics, religion, or finance. This type of discussion would be focused on providing valuable insights and exchanging opinions, rather than making jokes and teasing each other. So, if you are looking to have a serious conversation, you should avoid bantering and use more formal language and tone.