Touya also served cake as a waiter in either book 5 or 6 of the manga to Kaho, Yukito, Syaoran and Sakura.
His jobs are mainly to keep an eye on Sakura. That's why he asks Yue to watch out for her after he gives away his power, as he ahsn't got the sixth sense ability to guess where she'll be now....so he won't be able to follow her under the cover of 'jobs'