Received my Tesco Clubcard with TnG too.
Tried to link the new clubcard to my Tesco online account, but failed.
Called the CS at 1300 number behind the card and got the following info to share with all:
1. Old clubcard is linked to new clubcard.
2. Old card's points will be transferred into new card and just continue with new card.
3. Swipe new card to activate and then call CS to link to online account.
4. Can reload TnG without charges but CASH only. Min is RM10.
5. Can pay purchases in Tesco via TnG at dedicated counters only.
6. No new card (with TnG) will be issued to replace Supp Card. Continue to use old supp card.