Here is a simple script to check which tables are missing trandata and generate the GG (so call DDL) to enable it on them.

select ‘add trandata ‘||t.owner||’.’||t.table_name stmt
from
(select owner, table_name from dba_tables) t,
(select owner, table_name from dba_log_groups) s
where t.owner = s.owner (+)
and t.table_name = s.table_name (+)
and s.table_name is null
and t.owner in
(‘<schema>’);