They are both grammatically correct. They do not mean exactly the same. If you are at the party, you could phone someone and say "Bring the children to the party". If you and the children are not at the party, you could take them there.
For somebody who's not already at the location, then 'bring' suggests that you'll be attending the party along with your kids, while 'take' suggests you'll just drop the kids off, but not attend it yourself.