If you are not required to pre-authorize payment then they will be in the Cart once accepted, and you can "Request a total" from the entry for one of the items if the seller has not set up automatic calculation for combined shipping of multiple items from that seller, or simply pay for them all without any adjustments if that's what you want to do.
While you get 1 hour to check out if you win an auction with the winning bid (I suspect you mean "offer" instead of "bid" since you refer to "accepted bids" and seller "acceptance" is not a part of the auction bid process) where you did have to pre-authorize, that is rarely enough time to combine shipping with other items from the seller (unless s/he has set up automatic combination or is breathlessly waiting for you to finish buying to send out an invoice--and I'm not even sure if s/he can for pre-authorized payments--and you to pay it). eBay said a few weeks ago that it would start testing on longer time for manual checkout after winning to give more time to combine shipping, but I haven't seen any posts from anyone who mentions having been given that option.
