Emission surface act like a down area light -- Not 360 degree This is a low-resolution rendering clearly showing that the NEON are lighting down instead of all around.  Something should be set differently ?  Something to try ?
The only difference between the 2 rendering (picture) beside the wall texture is that I needed to add more subdivision :  From 4 to 6.  Without these added subdivision, there were black spots in the final rendering.  However, the lighting was defective the same way.
The NEON are set up according to the tutorial of Blender Guru (Regarding NEON part 1 and 2).  I don't mind sharing any information.  I am just currently limited to 128 kbits/s for the next 5 days.

Here, the exact same rendering with another wall texture­...  Exact same: Colour artefact because of the 95% JPEG Compression.
The way a surface responds to light depends on the direction that particular point on the surface is facing. The direction of a point on the surface is determined by the 'Normal' of that surface. The Normal can be determined either by the actual surface geometry or this can be overridden by your Normal Map.
In your particular case, the way the surface seems to be reacting to the light, the way the surface seems to be reacting to the light indicates that the normal is generally pointing 'up' and to the 'right' - ie, it's only responding to light from that direction. As this is different to the apparent geometry, this indicates a problem with the normal - especially since the problem goes away when rendering with a different wall texture.
There is a problem either with your Normal Map itself or with how you are connecting the Normal Map to your material's nodes (impossible to say without seeing either the normal map or the nodes).