The spell that is used to summon a rainbow is "Go n-éirí an bóthar leat". It translates to " May the Road Rise With You".
When Phoebe is granted luck, she receives a visitor. One of the people she mentions it could be is Justin Timberlake. In real life, Alyssa Milano (Phoebe) dated him.
Jason Dean's Internet Alias Cyrano comes from the famous Edmond Rostland play Cyrano de Bergerac where, Cyrano has many doubts about himself because of his large nose so he talks to his love through someone else to try to win her heart. Just like how Jason did only he did it through a different alias online to try to win Phoebe's heart without her knowing that it's him.
The spell used by the Leprechauns and the demon Saleel to grant good luck is "Sláinte is táinte". This translates to "health and wealth".
When Neil Giraldo and Pat Benatar are speaking to Sheamus, Neil tries to ask Sheamus for more luck and Sheamus replies "I already hit you with me best shot" which is a clever reference to Pat Benatar's hit song "Hit Me With Your Best Shot".