Is there a recommended number of triangle or poly count for a scene= characters+ environments for Unity in IOS, iphone.etc?,What is recommended the polygon limit For a 3d scene in Unity plus characters+environment?
if you are asking for performance, polygon count is not THAT important, i have seen 2M polygon count scene outperform 5k.
material count, light count and most important batching is playing the important role when it comes to performance.
Search Draw call and static-dynamic batching topics it will help you a lot.
about your question, every iPhone model has different hardware specifications so we can not generalize these numbers for ios, out of my experience I can say that you should try to stay below than 1m tris count for mobile if your scene stays static, otherwise cut this number the half, 500k would be a viable number.
but please note that all this numbers does not mean much thing. for example I have a scene with 9.8M tris and it is works perfect with samsung note 5.
so conclusion; batching is the key here, not polygon count.
7000-10000 vertices, 5000 skinned, 40-100 objects screen (Iphone 2 and below/Android)
30000-40000 vertices, 15000 skinned, 70-200 (Iphone 3, Iphone 4G/Android)
Beginning 3D Game Development with Unity: 2011
Has the number changed for the newest Iphone/android?