Yesterday, I wrote two comments that got upvotes, but these don't show on the daily reputation score section. Was there any issue yesterday? Does it take time to update? Or am I missing something about how reputation works with comments?
You receive no reputation for commenting on the site. Commenting works like Whose Line is it Anyway?, the points are all arbitrary.
You don't get reputation for comments. You only earn reputation for questions and answers.
The votes only matter when there are so many comments that the entire list is initially collapsed. In that case, the highest-rated comments are the ones that are shown.
Comment votes DO NOT add to your reputation at all.