If you start counting the tiles you will also notice that current position is better by far when it comes to food-income. The approach is maybe effective the first rounds, but will stagger the city afterwards. In this calculation I did not add the improvements.
After counting both positions:
Current start: 37 food, 14 Commerce, 14 hammers. Pro's: Plantation will increase commerce greatly later, Defense bonus by river and hill, fair commerce, all tiles usable, 4 flood plains. Con's: Bad health
Fair spots for cottages: 4 flood plains+ 4 grassland
Bananas: 34 food, 10 commerce, 15 hammers. Pro's: Early bananas, fair production. Con's: Desert Tile.
Fair spots for cottages: 2 flood plains+ 5 grassland
I'm not sure how you are counting the food (I assume you are adding up the base food of all the tiles)
The more relevant analysis would be what food surplus each capital would have at each size
bananas
at pop 2 working corn, deer it has a food surplus of 10
at pop 3 working corn, deer, cottaged FP is has a food surplus of 11
at pop 4 working corn, deer, 2 cottaged FP is has a food surplus of 12
at pop 5 working corn, deer, 2 cottaged FP, cottaged river grass tile is has a food surplus of 12
6 pop (add plains riverside cottage) 11 excess food 4 riverside cottages
7 pop (add plains riverside cottages) 10 excess food 5 riverside cottages (-1

without a granary and just corn if we keep a forest and the deer forested)
8 pop (add grass cottage) 10 excess food 5 riverside, 1 non cottages (-1 with a granary and just corn)
9 pop (add grass cottage) 10 excess food 5 riverside, 2 non cottages (-1 with a granary, corn and deer)
10 pop (add grass cottage) 10 excess food 5 riverside, 3 non cottages (? )
11 pop (add grass cottage) 10 excess food 5 riverside, 4 non cottages (? )
SIP
at pop 2 working corn, farmed banana it has a food surplus of 8
at pop 3 working corn, farmed banana, cottaged FP it has a food surplus of 9
at pop 4 working corn, farmed banana, 2 cottaged FP it has a food surplus of 10
5 pop (add FP cottage) 11 excess food 3 riverside cottages (-1

without a granary and just corn)
6 pop (add FP cottage) 12 excess food 4 riverside cottages (-1 with a granary and just corn)
7 pop (add grass riverside cottage) 12 excess food 5 riverside cottages (-1 with a granary corn and deer)
8 pop (add grass riverside cottage) 12 excess food 6 riverside cottages (? )
9 pop (add plains riverside cottage) 11 excess food 7 riverside cottages
10 pop (add plains riverside cottage) 10 excess food 8 riverside cottages
11 pop (add grass cottage) 10 excess food 8 riverside cottages 1 non