In was just reseacrhing all of the symbols that were represented on the stained glass in the church and stumbled across this (the wheel was in the bottom left corner of the glass). I think this mirrors the wheel on the island too and is interesting:
The wheel (Skt. chakra; Tib. 'khor lo) is one of the most important Buddhist symbols, as it represents the teachings of the Buddha. The Buddha was the one who "turned the wheel of the dharma" and thus the wheel symbol is the Dharmachakra, or "wheel of law." The Tibetan term for this symbol, chos kyi'khor lo, means "the wheel of transformation."
The wheel also represents the endless cycle of samsara, or rebirth, which can only be escaped by means of the Buddha's teachings. And some Buddhists regard the the wheel's three basic parts as symbols of the "three trainings" in Buddhist practice: The hub symbolizes moral discipline, which stabilizes the mind. The spokes (usually there are eight) represent wisdom which is applied to defeat ignorance. The rim represents training in concentration, which holds everything else together.
Some Tibetan wrathful deities are depicted brandishing a wheel as a weapon to conquer evil and ignorance. This theme may have been adapted from Hindu iconography, in which a disc is an attribute of the god Vishnu and a symbol of the absolute weapon that conquers desires and passions.