Q: Are Scopus indexed journals part of the Thomson Reuters journal list?
Scopus and ISI Web of Science (previously owned by Thomson Reuters and currently by Clarivate Anlytics) are two different databases. While most journals would get indexed in one of the two indexes, some journals might want to get indexed in multiple databases for greater visibility.
Not all Scopus indexed journals would be indexed in ISI as the inclusion criteria for ISI are more stringent, but some of the top Scopus journals might eventually make it to the ISI journal list.
You can use the Clarivate Analytics Master Journal List to find out whether your target journal is indexed in ISI. Just type the journal's name or ISSN in the search box and check its coverage in the results. If the journal is indexed in Science Citation Index or Social Science Citation Index, it means that the journal is ISI indexed.