The thing with causal, on/off hook-ups is they're just that: casual and on/off. So, five-hour flight for a bang? Sure, why not. But a 14 hour flight - not feeling it, not even for birthday/Valentine's bang (even though they're the best bangs going!).
So, casual/hook-up THEO may still be alive - if not 'kicking.'
They may continue to 'see' each other when possible/preferable until either begins a new/serious relationship with someone else.
That having been said, Miss On-set Romance seems to have an MO: Boyd (worked together, got together), TH (worked together, got together). It could be the case that the romance bug bites on the set of this next movie (though probably not with Renner).