can you have 2 apple watches on the same iphone

Yes with the following stupupation:

1. You can have have 2 (or more) watches setup for yourself but you can only use one at a time
2. You have have watch(s) setup for yourself and also have watches setup for family members who do not have their own phone. Note that not all countries support Family setup. The countries are listed need the end of:
3. For how to setup family watchs see: Set up Apple Watch for a family member - Apple Support

Yes;