Can I have two apple watches synced to the same iPhone?

Yes, but only one of them can be actively paired to the iPhone

https://9to5mac.com/2018/10/15/iphone-with-multiple-apple-watches/

You can use Apple Watch Family Plan to enable Apple Watches for dependent children, or whoever you want to be managed by your iPhone. These Apple Watches have limited features, as they are not allowed full access to the data on your iPhone, that a paired Apple Watch is allowed.

https://support.apple.com/en-us/HT211768

https://www.apple.com/newsroom/2020/09/apple-extends-the-apple-watch-experience-to-the-entire-family/