Originally Posted by safigan

I've helped my son get multiple bonuses on multiple AmEx cards even while holding a related card. I think the 9/16 and 8/17 entries below satisfy the criteria you're looking for, albeit for the business card.

6/16: 100k for AmEx Plat Personal
9/16: 75k for AmEx Gold Business
3/17: 30k for retention bonus
3/17: 10k for line-of-credit enrollment
5/27: 10k for line-of-credit enrollment (different card)
8/17: 75k for AmEx Plat Business
2/18: 10k for retention bonus

Total: 310k in bonuses (warning: required substantial spending, especially for the business cards; required substantial annual fees)