I know two Elianas, both about my age (mid-20s). They both pronounce it El-ee-ah-na. Doesn't feel trendy to me, but it's not my thing.
I don't like the ah-na prn at all, I find it very nasally. And I don't like the nickname Ellie much either. Guess this is the sort of name I'd never ever end up liking, sorry. There's nothing wrong with it as a name per se, though it does come across a little trendy, I just don't like it.
Yes I like Eliana and would prn it el-ee-ah-na. I do prefer the spelling Elleana.