,أحسن الله إليك Is saying "Allahumma Aameen" or "Aameen ya rabbal 'alameen" or "Aameen thumma aameen" a bid'ah? !بارك الله فيك وأكرمك أستاذ

Ustadh AbdulAziz al-Haqqan
The 1st two, this is du'a', as for the last one I have never heard an answer from a scholar regarding it.