DLR to BankorDLR and Jubilee line to Westminster?

The short answer

For one traveler they cost the same. That does not change up to 8 travelers.

The DLR and Jubilee line to Westminster is quicker: 22 min against 23 min.

DLR to Bank: 05:25–00:15. DLR and Jubilee line to Westminster: 05:25–00:05.

Priced against each other

Whole-party totals · adult fares

What each costs for the whole party, in GBP. The cheaper of the two is marked on every row.
Travelers	DLR to Bank	DLR and Jubilee line to Westminster	Difference
1	£3.30	£3.30	same
2	£6.60	£6.60	same
3	£9.90	£9.90	same
4	£13.20	£13.20	same
5	£16.50	£16.50	same
6	£19.80	£19.80	same
7	£23.10	£23.10	same
8	£26.40	£26.40	same

Where each one leaves you

DLR · Transport for LondonDLR to Bank

From: London City Airport DLR station
To: Bank, in the City of London, calling at Canning Town, Limehouse and Shadwell
Runs: 05:25–00:15
Journey: 23 min

The paper single from the machine is £7.00, more than twice the £3.30 tap fare for the same train.

Not every DLR from the airport goes to Bank; some run to Stratford International. Check the platform display.

DLRJubilee · Transport for LondonDLR and Jubilee line to Westminster

From: London City Airport DLR station, changing at Canning Town
To: Westminster, via Canary Wharf, London Bridge and Waterloo, continuing to Green Park and Bond Street
Runs: 05:25–00:05
Journey: 22–27 min

Change at Canning Town, the third stop: every DLR from the airport calls there.