A "bellini" is a cocktail invented in the 1930s at Harry's Bar in Venice, Italy, by Giuseppe Cipriani. It's made with Prosecco, an Italian sparkling white wine, and white peach puree. It's a great way to get an evening started.
"Blini" are leavened Russian buckwheat pancakes traditionally served with sour cream and caviar. The slightly bitter buckwheat is a great foil for the unctuous caviar.
So you see, there is quite a big difference between the two.
I am not one who usually points out this kind of thing, but it's a sore subject for me. I once had a sous-chef who refused to call blini by their proper name. He always referred to them as bellinis, which always got my blood boiling. I thought that if he was going to be second-in-command at a three-star New York City restaurant and serve blini and caviar for $168/portion, he should know how to say it. Fair enough right? (Actually, what's worse is that I think he did know, and that it was his own special brand of taunting me.) So watching Valerie make bad blini in the second episode of Top Chef while at the same time mispronouncing the word, blini, was very irritating.
Thanks, I needed to get that off my chest.