You can do something like this, if you can rely on rn column:
select CustomerID
, MAX(CASE WHEN RN =1
THEN CITY
END) AS CITY1
, SUM(CASE WHEN RN =1
THEN Amount
END) AS Amount1
, MAX(CASE WHEN RN = 2
THEN CITY
END) AS CITY2
, SUM(CASE WHEN RN =2
THEN Amount
END) AS Amount2
from @t
GROUP BY CustomerID