More than definitely a bug, if you cannot access the area at all there is still a way to get there, of course this requires being on PC.
You can type this into the console:
movetoqt
It will teleport you to your quest marker.
You can also type:
coc [insert cell name here]
For example:
coc RocketLabTop
Will take you to the Repconn research labs.
Here is a list of the ID's for Repconn:
0007ea61 RocketLabBasement REPCONN Basement
00081d1f RocketLabMid REPCONN Facility
000e5a8d RepconHQ02 REPCONN Office 2nd Floor
000e5a84 RepconHQ01 REPCONN Office Main Floor
000e5a88 RepconHQ03 REPCONN Office Top Floor
00081cfa RocketLabTop REPCONN Research Labs
(The middle one is the ID)
Then once you finish using the console you then save and quit immediately, then reload the game. This is because opening the console will temporarily disable achievements, but they will become usable again if you reload the save. Of course you don't have to worry about this if you don't care about achievements.
Sources:
https://www.gamefaqs.com/boards/959559-fallout-new-vegas/57300640
http://fallout.wikia.com/wiki/Fallout:_New_Vegas_cell_ID