Can Ahri Alluring stack? Like if I have 2 on one BF, do I get 3 points from holding?

Yes, Ahri, Alluring's ability does stack.

If you control two copies of Ahri, Alluring on the same battlefield and you hold that battlefield, each of their triggered abilities will fire.

According to RiftJudge FAQ #6902:

• "Multiple Ahris holding battlefields can each trigger their effect on the same upkeep."
• "Multiple Ahris can be on the same battlefield and each will grant a point."

Therefore, for holding that battlefield, you would gain the standard 1 point for holding, plus 1 point from each of the two Ahri units, for a total of 3 points from that single battlefield.