When will bloom become queen of domino

She won't because Daphne is older and the next queen. She will most likely be the queen of Erakleon though.

Most royal families work whenever the father or mother has died that their child (If a girl or a boy) and their spouse will become the new rulers. So, whenever Mariam and Oritel decide to kick the coop, is when Bloom and Sky will become king and queen of Domino.

I think he will became the queen of Dominao when she will marry .But i don't think any winx will marry in the season 5 or 6.;)

She might not be queen of domino. She might be queen of eraklion. Since she has 2 kingdoms to rule if she will become queen. So, she should be queen in season 6. But it's really unknown for now.

Soon, because Bloom's life won't be perfect without the thrown. And we all know the creator of Winx is hellbent on making Bloom's life perfect...

Daphne is Crown Princess.
Bloom has no chance.