Bucky would tell Lightning what he knew in return, especially regarding the hidden entrance and the abilities of the scientists. Don't use metal weapons if you've got those, Lightning. Yeah.

He's already got a way of contacting the Rangar, so he wouldn't ask about the base. He would be curious about the sympathizer, just because he likes to know his allies so he doesn't accidentally murder them, but he wouldn't push it if she didn't answer.