Yes, Section 179 from your business can offset other "earned" income on the same tax return, including your spouse's business income. On a personal tax return (Form 1040), the 'business income limit' includes all businesses and all W-2s of both spouses.
However, you might not want to do that. Yes, it is saving you income tax now. But if you use a different depreciation method (less depreciation this year) so you have depreciation in future years, the future year depreciation can potentially reduce that year's income tax AND self-employment tax (assuming your business is profitable in the future year)..
