Can I use the same iCloud backup account for 2 separate phones?

Hello,

Yes, it will probably work if both phones are using the same Apple ID.

How to back up your iPhone, iPad, and iPod touch

If you have different Apple ID's, consider using family sharing: Family Sharing

Good luck.

I understand that you want to restore two iPhones from one iCloud backup.

Yes that is possible in normal circumstances.

It also depends which iPhone models you are referring to.

You may get better and prompt responses if you may kindly provide the iPhone Model that you have and the iOS version if it is known to you.