Amex Card 2 doubt?

I have a Amex Plat Travel and a supplementary one for my wife.

I've been using the Gyftr -Amazon pay approach to maximize points and I will hit the 4 Lakh milestone comfortably.

Question - Should I opt for a MRCC/Gold Charge (which one makes more sense) and is it better to refer my wife for it, So that I can get the referral benefit too?