After Marriott acquired Starwood hotels and after Marriott revamped their co-branded credit cards that are exclusively issued only by Chase and American Express last year 2019, Marriott made a decision to only allow 15 elite night credits per year for Marriott credit cards holders. It does not matter how many Marriott credit cards you have, you only receive 15 elite night credits per year as part of the credit card's annual benefit.

Good News: Marriott Bonvoy Now Allows 30 Elite Nights Per Year From Two Credit Cards (15 Personal & 15 Business)

What Change?

It appears that Marriott has changed the rule. It now allows 30 elite night credits per year from having two eligible Marriott Bonvoy credit cards:
  • 15 elite night credits from Marriott Bonvoy personal credit card.
  • 15 elite night credits from Marriott Bonvoy business credit card. 

Here's the email that I received from Marriott Bonvoy:

Great news! Because you have both a Marriott Bonvoy™ business credit card and an eligible Marriott Bonvoy personal credit card, you’re now receiving an additional 15 Elite Night Credits, on top of the 15 Elite Night Credits you received at the beginning of this year. 
You’ll continue to receive a total of 30 Elite Night Credits each year you maintain two eligible Cards.

Sure enough, when I logged into my Marriott's account. It shows that I have 30 bonus elite nights.

Why This Matters?

Receiving bonus elite night credits is one of the fast ways to help achieving the next tier of Marriott Bonvoy program. Having elite status can be beneficial to get complimentary preferred room upgrade, free daily breakfast for two, late check-out, bonus points, etc.  at worldwide Marriott Bonvoy hotels and resorts.