Is it advantageous to have an American/British/Australian/etc. citizenship over countries where English isn the native language?
It definitely is an advantage being a Native English speaker. However, the global demand for English is so much that it outstretches by far the number of Native English teachers available and this gap has been filled by qualified Non-Native teachers of English. Non-Native English speakers have needed to learn a second language and are seen as bringing to the classroom a particular understanding of the needs and requirements of foreign language students.