In the lead up to a millennium event the layout gets published, and as linked below a map and 3d illustrations are shown.
http://www.millennium-series.com/events.php?event=T4
The key on the map gives the official name of the bunkers- medusa, cake, cone etc.
But there can be other common names eg dorito and t-bag both describe the same bunker (because it looks a bit like a dorito chip/crisp or pyramid t-bag)
The thing you won't get is what individual teams use to name bunkers in their calls. Eg orange, Apple, tango, New York, Paris, etc
The name may be quite generic such as drinks can brands for the different ones in different positions or they could be random words the team have picked
If you're going to play with a team they need to familiarise you with their calls
http://www.millennium-series.com/images/events/fields/chantilly_2d_millennium-2015.jpg