I don't mean when someone sneezes or when someone's been kind to you, but in other situations.
Like, when someone is enjoying a lot of luck, fortune or doing staggeringly well in something.
Or when someone is wonderful at a task and you admire them at lot. So, you want to get to know them better through talking to them, either directly or via online messaging. However, they are often quite busy and you're hoping they have time for you, but they turn out not to have any. You can say: "(It's a pity, but) bless them."
Besides, is it the same meaning as "wish you good luck"?