Because it happened on the outbound and not on an EU airline, no EU comp applies.
However, the four hour delay on the inbound, since it happened at an EU airport, the airline was bound to provide for 'right for care' as outlined under Arcticle 9 of the
EU directive:
Article 9 Right to care
1. Where reference is made to this Article, passengers shall be offered free of charge:
(a) meals and refreshments in a reasonable relation to the waiting time;
(b) hotel accommodation in cases
- where a stay of one or more nights becomes necessary, or
- where a stay additional to that intended by the passenger becomes necessary;
(c) transport between the airport and place of accommodation (hotel or other).
2. In addition, passengers shall be offered free of charge two telephone calls, telex or fax messages, or e-mails.
3. In applying this Article, the operating air carrier shall pay particular attention to the needs of persons with reduced mobility and any persons accompanying them, as well as to the needs of unaccompanied children.
If you weren't provided with food vouchers and/or telephones as a result of the inbound delay, you are entitled to claim back, under the EU directive, any costs you had (maybe buying food, making calls - I once managed to claim £70 of calls since their lack of provision meant I was using a UK mobile to call another UK mobile, both of us in the Caribbean - very ouch!). It's not much, particularly with respect to your outbound, but it is your due.
Since you hadn't mentioned, it seems like you might not be aware.