That's a little confusing. You only ever get one bonus action on a turn — but this spell lasts a minute, which is ten turns. So, you can attack once as part of the casting — that takes the bonus action your first turn. Then, for nine more rounds, you have the option of using your bonus action to attack again.

This spell is spectacular because on those follow-up turns you can attack *and* cast other high-level spells, not just cantrips. And it is a very rare ongoing spell effect which doesn't require concentration — and so doesn't interfere with spells that do.