Can luciferin + ATP → luciferyl adenylate + PPi be reversed?
In theory every chemical reaction is reversible. 

The reaction that you mention does not emit any light yet, that comes later with the following reaction:
$$ \text{Luciferyl adenylate} + \ce{O2 -&gt;} \text{Oxyluciferin} + \text{AMP} +h\nu $$

Since the reaction you mentioned occurs under loss of pyrophosphate ($\ce{PP_{i}}$) which is where the energy was stored beforehand, I guess it's somewhat hard to get it back. 



It's almost like hoping that
$$ \ce{2CO2 + 3H2O -&gt; C2H5OH + 3O2} $$
occurs under room temperature. Which it doesn't, because $\ce{CO2}$ is such a thermodynamical black hole. I think the same applies to your question.