Rate today for GBP was 1SGD = 0.58275 GBP
I don't use YT.
Google search comes up 1SGD = 0.59 GBP, so still quite close.
UOB VS a day before was like 1SGD = 0.566 GBP.
Have to see ba, I think other than savings on the payment itself, there is not much rewards from YT (ie no benefit from top up, no benefit from spending)? So seems Grab card still offers more "rewards" for a relatively better rate.
So consider GBP1000 expense:
YT if give like google rates, is S$1694.92
Grab card will be like S$1716.00
If use get 8 to 10% rebate on Grab topup, already better than YT pricing, plus grab reward points. If you UOB PRVI card, then 2400 miles for the additional $21.08, not a bad choice, plus grab rewards points. If consider grab rewards converted to miles (not a very good use of grab rewards points IMO), then that is another 1920 miles.
If use UOB VS, is S$1766.78 and get 7060 miles. Not a very good choice, unless grab annual limit already exhausted.