Linked servers are for internal (transact-sql) use. As in stored procs or SQL code you send to the primary SQLServer. If you want to make use of tables on a linked server you would send SQL commands to your SQLServer referencing the linked server table. E.g. "INSERT INTO otherserver.db.owner.table SELECT a, b FROM tablex"
DTS is an external process. If you want to get to tables in your access database from DTS, set up a separate connection to with an ODBC DSN for that Access database.