What would happen if an aluminum wire were dipped dipped into a solution of tin (ii) sulfate?

When you add aluminum to a solution of tin (II) sulfate, the next reaction will happen:
3Al (s) + 2SnSO4 (aq) → Al3(SO4)2 (aq) + 2Sn (s)
Aluminum wire will dissolve, while tin will precipitate.

This can be proven by a standard potential for both half-reactions:
Sn2+ + 2e → Sn      E = -0.14 V
Al → Al3+ + 3 e       E = +1.66 V

The overall potential is positive (+1.66 V + (-0.14 V) = +1.52 V), which is a proof that this reaction will proceed spontaneously.