Is the child of zina considered an orphan or a stranded traveler with regard to sadaqa?

The child of zina (fornication/adultery) is neither an orphan nor a wayfarer. Therefore, he is not to be given from zakat unless his mother is unable to provide for him, or she dies and there is no one among his relatives who is obligated to support him, or if those who are obligated to support him refuse to do so. An orphan is not a recipient of zakat by virtue of being an orphan, but he may be a recipient if he is poor or needy or falls under any of the other eight categories mentioned in the verse from Surat At-Tawbah.