Answer to your question depends on several factors. What is your 33KV feeder rating. If one feeder cannot carry whole load of both transformers, paralleling will not gain much. If you feeder fails second one will be overloaded and trip. If your supply is from different stations in case that you parallel 33KV feeder you parallel both stations. Make sure that they are synchronized. Also if one of them is less loaded or have higher rating transformers (lower system impedance) it will take most of the load. If neither of above conditions is a concern you can parallel 33KV.
Second question is transformer rating. If each of transformers is able to carry the whole load of 11KV feeders then parallel them. If not failure of one transformer will lead to overload and trip of the second one, hence you lose the whole station.
Last question is equipment short circuit rating. If you parallel 33KV, system impedance will decrease (two parallel impedances). Same if you parallel transformers
. Make sure that your 11KV breakers are able to carry the short circuit current.