I think that city bonuses should be tied to seasons so cities have a chance to change it up should they get board with the bonus they have or just want to try something new.
On Aerhen we have 20 towns, if we had 20 different bonuses then each season each town could pick a new bonus. If we had 40 bonuses then each town could pick two which would be much more interesting.
To keep it competitive I see two options: the top guild picks first or it picks last (with 20 bonuses), or the top guild picks first and last (if 40 bonuses).
I think it would be best if we could do the second option as it would give motivation to be first while also not giving that first town total control over the 'best' bonuses.
Personally I would prefer if the top guild picked last and the bottom guild picked first to allow some balancing to occur but I realize that may be counterproductive to encourage competition for first.
Now that is over with, how about what these bonuses could be.
For anyone who knows me it should not come as a surprise that the first bonus I suggest is fertility.
Having a more fertile town for a season would directly reduce the amount of farming they need to do in order to maintain the upkeep of the town and how much space they need to commit to farming.
This fertility bonus could be a flat 150% as we had in Myr at the high fertility regions, or it could be spread out into smaller +XX% bonuses which collectively determined the towns fertility.
If it was spread out then we could have more bonuses to pick from and more chance of those bonuses being spread around instead of hoarded by one town. Say there were 5 +20% fertility bonuses available and 40+ total bonuses so each town picked two; this way the top town could grab one and through diplomacy or luck they could still get a second one by the end but would not have a total domination on the bonus. I do understand that this would reduce the value of said bonuses but I would think that being able to have multiple different bonuses as an option might be preferable to just one big one for the season.
Here are other possible bonuses which could be given as single big perks or broken up into multiple smaller ones:
reduced respawn timers on materials in the region
reduced gold sink on crafting costs in the region or town
reduced material costs on crafting goods in the region or town
+1 of a magical essence for any imbuing done in region or town (so if an imbue needs mind 10 now 1 pip is filled already and you just need to supply mind 9)
increased move speed in the region or on the regions roads
+1 of an ability mastery for all citizens of the town (like how imbued knowledge works)
+5% chance to get better quality items when crafted in town or region
bonus materials created when processed (wood, ingots, leather, cloth, charcoal, oils)
a potion effect on all players in town
decreased watering needs for farm plots in town
increased defenses or damage for any npc soldiers in the region (forts, mines, bridges)
increased wall durability of town
unique skin only available for the season for the guildmembers
reduced material processing time
world special mounts appear more frequently in that region
Town personal stargate