We usually have quite a few animal companions in our games, our Druids and Hunters tend to leave them outside when in metropolitan cities.
As for a speaking with your companion and not just an empathic link, Hunter can actually speak with their companion at level 11.
Well, now you have me looking at hunter lol. That seems to be what I was looking for with emphatic link and what not. Also plan to increase wolf int to 3 for ease of play.
Leaving animal out of town could work in some scenarios, but this next adventure has the enemy compound in town, and we either have to sneak in or bluff our way inside. I'd like to keep wolf with me so that's why trying to figure out way to make him look like a simple dog a merchant might keep around.
I don't know the context of your adventure, but if you really cant just bring your animal into town freely, you could maybe see if your DM will let you purchase a Figurine of the Concealed Companion, a Whistle of Calling, or have the Hosteling enchantment on your armor.
And if you don't like Hunter, there's the Circlet of Speaking, which just lets your animal companion talk.
You could use Reduce Animal and try to pass it off as a small dog.
The Hunter archetype Urban Hunter from Heroes of the Streets does what you want.
Disguise options:
There is the Carry Companion spell.
For a wolf, the Pup Shape spell might also work.
Every day or so you could just memorize Speak with Animals, no? At least once you are 4th as a Ranger, or 1st as a Hunter. I don't generally do that myself, and instead rely on the Wild Empathy bonus for doing Handle Animal and the tricks that it has been taught.