Hi Kamikasi
Your 29g tank is severely overstocked at the moment and I would in my opinion not be adding any more fish to that tank regardless of the size fish such as the neons. Besides that, your Angel fish more than likely would snack on the neons.I have cardinal tetras with my Angels and they do not bother them, but I have heard from others that the Angels would pose a danger to the neons.
If I were in this predicament I would look for a larger tank asap or return the Angel fish and one bristlenose pleco and the
red tail shark. That would leave you two Discus,and a BN pleco can live in the 29g tank for awhile, but you would soon have to upgrade to a larger tank..