Elected club points are good for the usage year that you elect no matter what the source of them is. For your 2027 elected club points, you can use them anytime upto 31 Dec 2027, for a reservation by 31 Dec 2027, subject to availability. You can borrow them forward into 2026. If you want bank them look up owner benefit level in your account and see the banking deadline associated with your owner level. Yes you can bank them to 2028 and combine them with 2028 club points. You can also combine them with any Club points you get as an incentive for attending a presentation or club points that you rent from another owner (subject to the usage years matching).
If you ae planning to use club points for a reservation that is after the banking deadline for the points, its a good idea to borrow club points rom the following year to make those reservations. that way if you have to cancel they go back to the usage year they came from and you have longer to find a use for them.