Can Spiritual Weapon Flank

It is not a person, a character, or an ally who is the spiritual weapon. It's a result of a spell. It doesn't allow for flanking or chance attacks.

Does bless count on spiritual weapon?

Could you cast a standard spell like guiding bolt while using spiritual weapon and maintaining Bless concentration? That's all right. Casting a spell as a bonus action is not the same as receiving a bonus action from a spell.

Evocation

As you direct it, a weapon formed of pure force springs to life and assaults opponents at a distance, causing 1d8 force damage each hit, with +1 point per three caster levels (maximum +5 at 15th level). The weapon takes the form of a weapon preferred by your deity or a weapon with spiritual importance or symbolism to you (see below), and has the same threat range and critical multipliers as a genuine weapon of its type. It attacks the target you choose, beginning with one attack in the round the spell is performed and continuing each round on your turn thereafter. It uses your standard attack bonus plus your Wisdom modifier as its attack bonus (potentially allowing it to attack numerous times per round in subsequent rounds). Because it is a spell rather than a weapon, it can inflict damage on creatures that have damage reduction. It can strike incorporeal entities as a force effect without the regular miss probability associated with incorporeality. The weapon always comes at you from the front. It does not receive a flanking benefit or assist a combatant in obtaining one. The weapon is unaffected by your feats or battle actions. The weapon returns to you and hovers if it travels beyond the spell range, out of your sight, or if you are not commanding it.

After the first round, you can use a move action to redirect the weapon to a new target each round after that. If you don't, the weapon will continue to attack the target from the previous round. Every time the weapon switches targets, it receives one attack. If your base attack bonus allows it, subsequent rounds of assaulting that target allow the weapon to perform repeated attacks. Use the spell's range, not the weapon's usual range increment, and switching targets is still a move action, even if the spiritual weapon is a ranged weapon.

Physical strikes have no effect on a spiritual weapon, but dispel magic, disintegrate, a sphere of annihilation, or a rod of cancellation do. The AC of a spiritual weapon against touch attacks is 12 (10 + Tiny object size bonus).

If an assaulted creature has spell resistance, the first time the spiritual weapon strikes it, you must make a caster level check (1d20 + caster level) against that spell resistance. The enchantment is dispelled if the weapon is successfully resisted. If not, the weapon's full effect on that creature will be applied for the duration of the spell.

Your weapon is frequently a force duplicate of your deity's own weapon. A cleric who does not worship a deity is assigned a weapon based on his alignment. A neutral cleric without a deity can construct a spiritual weapon of any alignment as long as he is behaving in accordance with that alignment in general at the time. The following are the weapons connected with each alignment.