No, have access to lounges via One World Status

CrashAndBurn:

 

Question is if it is worth it considering the $1250 annual fee.

 

It's no longer available on the NZ website. I think it's grandfathered. Last time I asked earlier this year not even existing cardholders can transfer onto it. In my experience, the majority of Priority Pass lounges are nothing to write home about. I wouldn't pay the guest fee under the Amex scheme.

Since the OP is transiting Singapore, there wouldn't be much of an issue not having Priority Pass access as the terminals are fantastic. If you have time head into the Jewel. If you are looking to rest, there are a number airside pay lounges with beds. There is one with a decent swimming pool as well!

That said I do have an NZ Westpac World Mastercard that does seem to allow 1 free guest in Priority Pass lounges, e.g. Strata Auckland and Plaza Premium Sydney. Different cards have different guesting arrangements it seems.

Asteros:

 

It's no longer available on the NZ website. I think it's grandfathered. Last time I asked earlier this year not even existing cardholders can transfer onto it. 

 

Correct, it was not that popular due to high fee and no Centurion Lounges in NZ, existing customers can keep their card