Ok, got around to watching it.
Basic info:
Get Bastion at level 5
Bastion Turns take place every 7 days or so in game, although this is flexible
The orders that can be given during a Bastion Turn are: Craft, Empower, Harvest, Maintain, Recruit, Research, and Trade.
29 special facilities available. A bastion gets two at level 5, a third and fourth at level 9, a fifth at level 13, and a sixth at level 17.
The special facilities are: Arcane Study, Armory, Barracks, Garden, Library, Sanctuary, Smithy, Storehouse, Workshop, Game Hall, Green House, Laboratory, Sacristy, Scriptorium, Stable, Teleportation Circle, Theater, Training Room, Trophy Archive, Meditation Chamber, Menagerie, Observatory, Pub, Reliquary, Demi Plane, Guild Hall, Sanctum, War Room.
Some special facilities are customizable – they mention the Garden as one of these.
There are examples of guilds (for the Guild Hall), like Adventurer’s Guild, Thieves’ Guild, etc.
There will be a Bastion tracker sheet available for players.
Read more at this site