The relationship is built for each sim seperately. I've literally never had 5 hives at the same time, but I had 3 at one point in my current household and, at first, I had two different sims bonding with them. 1 bonded with one hive and the other with 2...just to save a little time so both sims had more time for other things. Eventually one sim did end up bonding with all 3, because she had far less going on (and thus more time).
As far as my routine, I just did bonding once or twice per day with each hive, right before doing the gardening. I know you can rush it along by doing it more frequently but I didn't bother because it goes up relatively quickly even doing it just once per day (per hive).
The one sim that does it still has the same morning routine:
1. Feed insects (just 1)
2. Nurture insectsx2
3. Feed Seymour (cow plant)
4. Get honey and beeswax from all hives.
5. Harvest all harvestables.
6. Make friendly with any bunnies that are out and have reduced relationship bars
It takes her 3-4 hours sim time to do all that.
Her husband's routine takes similarly as long but his is to care for all the animals (2 chicken coops, 1 cow and 1 llama) and make friendly with all the birds.
Beacause of the bees, bunnies and birds, they never have to do actual garden tending other than harvesting. Sprinklers do the watering, bees do the fertilizing, bunnies do the weeding and the birds take care of the bugs.