Would I have enough power?

Having completed my first DIY speaker build in years (Seas A26), I'm really wanting to try a lower power tubed amp again. The A26 is a true 88dB efficient, 8 ohms minimum speaker, with an ultra-simple x'over too, no less.

I listen mostly at moderate levels, with the occasional loud burst, but my open floor plan room's on the large size (speakers 7' apart, me 9' back, another 10' behind me, to my left is the dining area).

In your experience, am I good with 10-15 clean watts here, or stick with EL34, etc. ?