You did not mention your arrival flight into BKK but think the normal time limit for interlining luggage is 4 hours or the first direct flight, whichever is longer. If you should be arriving on CX 709 (23:50) your TG flight must be the first direct one in the morning, e.g. TG 673 (0700). This rule is not always be enforced but be mindful. Check with CX before booking your TG ticket.
Someone please correct me if I am error.