Thelema, the occult system and philosophy developed by Aleister Crowley, incorporated the concept of Obeah, as well as that of Wanga (of Vodoun, similar to Obeah) into his system. There is truly only brief mention, but it is an interesting example of a Caribbean tradition influencing a Western tradition. From The Book Of The Law (AL I:37):
Also the mantras and spells; the obeah and the wanga; the work of the wand and the work of the sword; these he shall learn and teach.
The only time Crowley commented further on what he meant by this, after much speculation on if he had begun to incorporate Caribbean or African traditions, was in his Commentaries:
The obeah is the magick of the Secret Light with special reference to acts; the wanga is the verbal or mental correspondence of the same.
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The “obeah” being the acts, and the “wanga” the words, proper to Magick, the two cover the whole world of external expression.
Obeah, to Aleister Crowley, was therefore the action portion of performing a spell or ritual. The wanga was in fact the expression of the act. Tracing a pattern to Eshu would thus be obeah and the incantation to Eshu would be wanga. Similarly, the intent of the spell alone would be wanga. Obeah and Wanga are thus the two elemental aspects of magic when used in the Thelemic context.
Obeah Spells 
Interesting Perspective on Obeah from a Thelemite who also loves Jamaican and African Culture. Much Respect!
I am from a different lineage in Obeah… I have no idea what Crowley’s visionary experience was communicating to him though I would relate the trance/energy/focus as Obeah and the trappings and rites in the objective world as the Wanga… Like a Wanga in traditions is often a fetish or talisman and Obeah is a force that in some practices empowers objects to become as talismans…