The wolves should spawn in the groves biome, however, since the groves biome is mostly covered with snow, they cannot spawn there. This is backed by the fact that the minecraft:spawns_on_block_filter doesn't cover minecraft:snow in the spawn rules to make them possible to spawn on the snow block.

The spawn_rules in the current beta:

{
        "minecraft:spawns_on_surface": {},
        "minecraft:spawns_on_block_filter": [
          "minecraft:grass",
          "minecraft:podzol",
          "minecraft:dirt"
        ],
        "minecraft:brightness_filter": {
          "min": 7,
          "max": 15,
          "adjust_for_weather": false
        },
        "minecraft:weight": {
          "default": 8
        },
        "minecraft:herd": {
          "min_size": 2,
          "max_size": 4
        },
        "minecraft:biome_filter": {
          "test": "has_biome_tag",
          "operator": "==",
          "value": "grove"
        }
      }

How to Reproduce
1. Find a grove biome.
2. Try /tp @s @e[type=wolf] to check if they spawn in the grove biome.

Expected Result
Some wolves spawn in the grove biome on snow block.

Observed Result
They don't spawn in the grove biome, instead they spawn outside of it when you teleport to them.