I suggest if you are asking if you aren't going to enter a park, whether you can dine at the resorts, the answer is yes.
However, if you're taking Disney transportation (and I can't assume that, but I can't help it!), do NOT take the bus to Epcot. You won't be able to get to the resorts that way.
Instead, take the bus to Disney's Hollywood Studios, and head to the boat dock just across the plaza from the bus drop off area. The boat stops at the Swan/Dolphin dock, the Boardwalk dock, and the Yacht/Beach Club dock before heading to the Epcot International Gateway dock.
There is a walkway nearby, but I don't suggest it to people who never knew it was there in the first place. It's not well marked.
If you had taken a bus or parked at Epcot, you'd be at the wrong side of the park to get to the resorts, and you wouldn't be allowed to cross through the park without a park pass. You'd still have to take a bus from Epcot to DHS if you wanted to be the right location.