First of all, what causes bendy light? According to the laws of physics, light cannot bend. It can appear to bend in two cases:
1) Moving between mediums that have different indices of refraction.
2) Space-path bent by gravity.
Since gravity does not exist in FET theory, we can throw out that explanation. On to the remaining explanation:
Light appears to change direction when passing through mediums with different IOR's because photons are sped up or slowed down by these mediums, changing their angle to the normal. For light to bend in a curved path (as required by FET), there must be a gradient IOR, layered mediums with different IOR's or mediums that have increasing or decreasing IOR's in a certain direction. Therein lies the problem: 'bendy light' is observed everywhere in the world at any time, which means that light is being bent in a practically infinite amount of directions. For gradient IOR to work in this case, there must be multiple IOR gradients in every possible direction and location, and these would overlap, destroying the effect. Therefore, there is no valid way to explain 'bendy light': it is an invalid theory.
If you manage to explain your way out of that, here's my next situation (assuming bendy light somehow exists):
According to FET (Tom Bishop), sunrise and sunset can be explained by 'bendy light', as shown in this diagram:

But what about the stars? You can see stars near the horizon at night, when there is no sun visible. So why can't you see any sunlight? With the sun being much brighter and closer, and the atmosphere being so 'thick', there would surely be some (a lot) of visible diffuse light.
Why can the same set of stars be seen on opposite sides of the southern hemisphere? If light could bend that much, than once again, why can you not see the sun? Why can't you see northern-hemisphere stars, since they are much closers?
These arguments should also applies to the moon's 'cold light'.
Also, explain how/why 'bendy light' changes during the annual cycle as shown here (only appears to affect the sun):
http://theflatearthsociety.org/forum/index.php?topic=24827.msg556818#msg556818Please feel free to answer my quoted question while you're at it:
http://theflatearthsociety.org/forum/index.php?topic=25098.msg553548#msg553548 - it seems that Rowbotham is accurate to a degree he shouldn't be, yet is very vague and uses estimations only when it helps his flat earth theory.