There is a definite second reference to ENT in the movie. McCoy talks about a vaccination to Melvaran mud fleas, which he injects into Kirk to make him appear sick. Melvaran mud fleas were mentioned once in Star Trek...the ENT episode "Canamar" (http://memory-alpha.org/en/wiki/Melvaran_mud_flea)
Coolness!
Coolness!
Aren't Melvaran mud fleas a reference to the Futurama episode "Where No Fan Has Gone Before" with Mellvar? If so, is that a reference recursion? 

