Dose Norton secure VPN app protect iOS iPhone
It depends on what you mean by protect your iPhone. The VPN will mask your location and encrypt your data as it leaves your phone and then decrypt the data as it returns to your phone. But it does not provide any malware protection.
There is no malware protection in Norton 360 on an iOS device. See this article from howtogeek . com for an explanation of why it is not necessary.
https://www.howtogeek.com/352613/what%E2%80%99s-the-best-antivirus-for-iphone-none/