Yeah tree roots can pose a risk to ponds, but a lot depends on whether the tree's roots grow primarily down or across and how generally invasive they are- i "think" pine tree's roots grow downwards, so should be ok, but don't count me on that. Make sure you line the pond with building sand, then underlay, and then the liner as this will help prevent roots coming through the liner. Also make sure there aren't any rocks in the pond hole as these can also puncture it over time.
My pond is very close to an australian tree off some sort (i think its a bottle brush tree or something like that) but it is fine being so close to such a tree since australian trees grow their roots directly downwards and not across (like willows) so they can take advantage of deep water levels in drought etc- either way, the soil in my area is so thick with pure clay, even if the liner was punctured it wouldn't drain because of all the clay in the soil.
My mum used to have a small pond under some pine tree's once, it was a big hassle though as numerous times a year we had to scoop all the needles out of the pond, the goldfish seemed to be ok though.