Yes, You have to teach an illusion to another guild member, however they have to know the illusion you are teaching. I dont remember if you have to teach the one you are working on or if you can teach any of them to get credit.

Type GLD in game to get all the guild info about tasks, reps, and ranks.

Player of Malisai

For Illusion tasks.. normally, every other tuesday(such as tonight) the Faendryl Enclave offers help from about 9pm-10pm, depending on availability and interest.. teaching, learning, etc with illusions.. in the wayside inn garrette.. They tend to be offered in illistim at the same time, as well. Just in case you have trouble finding someone. This is on hold, however, till EG is over.